Dr Caroline Leaf – Contradicted by the latest research

This is my most popular post by far.  I truly appreciate the support and interest in this post, but I’ve discovered and documented a lot more about Dr Leaf’s ministry in the last two years.  I welcome you to read this post, but if you’d like a more current review of the ministry of Dr Caroline Leaf, a new and improved version is here:
Dr Caroline Leaf – Still Contradicted by the Latest Evidence, Scripture & Herself

* * * * *

Mr Mac Leaf, the husband of Dr Caroline Leaf, kindly took the time to respond to my series of posts on the teachings of Dr Leaf at Kings Christian Centre, on the Gold Coast, Australia, earlier this month. As I had intended, and as Mr Leaf requested, I published his  reply, complete and unabridged (here).

This blog is my reply.  It is heavily researched and thoroughly referenced.  I think it’s fair to say that while Dr Leaf draws her conclusions from some scientific documents, there is more than enough research that contradicts her statements and opinions.  I have only listed a small fraction, and only on some of the points she raised.

In fairness, the fields of neurology and neuroscience are vast and rapidly expanding, and it is impossible for one person to cover all of the literature on every subject.  This applies to myself and Dr Leaf.  However, I believe that the information I have read, and referenced from the latest peer-reviewed scholarly works, do not support Dr Leaf’s fundamental premises.  If I am correct, then the strength and validity of Dr Leaf’s published works should be called into question.

As before, I welcome any reply or rebuttal that Dr Leaf wishes to make, which I will publish in full if she requests.  In the interests of healthy public debate, and encouraging people to make their own informed decisions on the teachings of Dr Leaf, any comments regarding the response of Mr Leaf, Dr Leaf or myself, are welcome provided they are constructive.

This is a bit of a lengthy read, but I hope it is worthwhile.

Dear Mr Leaf,

Thank you very much for taking the time out to reply to some of the points raised in my blog.  I am more than happy to publish your response, and to publish any response you wish to make public.


I published my blog posts to open up discussion on the statements made by Dr Leaf at the two meetings that I attended at Kings Christian Centre on the Gold Coast.  As you rightly point out, people should be able to make informed decisions.  A robust discussion provides the information required for people to make an informed choice.  Any contributions to this discussion from either yourself or Dr Leaf would be most welcome.

I apologise if you interpreted my blogs as judgemental, or if you believe there are any misunderstandings.  You may or may not have read my final two paragraphs from the third post, in which I acknowledged that I may have misunderstood where she was coming from, but that I would welcome her response.  If there were any misunderstandings, it is likely because Dr Leaf did not make any attempt to reference any of the statements she made on the day.  You may argue that she was speaking to a lay audience, and referencing is therefore not necessary.  However, I have been to many workshops for the lay public by university professors, who have extensively referenced their information during their presentations.  A lay audience does not preclude providing references.  Rather, it augments the speakers authority and demonstrates the depth of their knowledge on the subject at hand.


It’s interesting that you feel the need to resort to defence by association, and Ad Hominem dismissal as your primary counter to the points I raised.

Can you clarify how attending the same university as Dr Christaan Barnard, or a Nobel laureate, endorses her arguments or precludes her from criticism?  I attended the University of Queensland where Professor Ian Frazer was based.  He developed the Human Papilloma Virus vaccine and was the 2006 Australian of the Year.  Does that association enhance my argument?

Can you also clarify why a reference from a colleague was preferred to letting Dr Leaf’s statements and conclusions speak for themselves?  Dr Amua-Quarshie’s CV is certainly very impressive, no doubt about that, although he doesn’t list the papers he’s published.  (I’m assuming that to hold the title of Adjunct Professor, he’s published peer-reviewed articles.  Is he willing to list them, for the record?)

Whatever his credentials, his endorsement means very little, since both Dr Leaf and Dr Amua-Quarshie would know from their experience in research that expert opinion is one of the lowest forms of evidence, second worst only to testimonials [1].  Further, both he and Dr Leaf are obviously close friends which introduces possible bias.  His endorsement is noteworthy, but it can not validate every statement made by Dr Leaf.  Her statements should stand up on their own through the rigors of critical analysis.

On the subject of evidence, disparaging your critics is not a substitute for answering their criticism.  Your statement, “By your comments it is obvious that you have not kept up to date with the latest Scientific research” is an assumption that is somewhat arrogant, and ironic since Dr Leaf is content to use superseded references dating back to 1979 to justify her current hypotheses.


In the blog to which you referred, Dr Leaf makes a number of statements that are intended to support her case.  These include the following.

“A study by the American Medical Association found that stress is a factor in 75% of all illnesses and diseases that people suffer from today.”  She fails to reference this study.

“The association between stress and disease is a colossal 85% (Dr Brian Luke Seaward).”   But again, she fails to reference the quote.

“The International Agency for Research on Cancer and the World Health Organization has concluded that 80% of cancers are due to lifestyles and are not genetic, and they say this is a conservative number (Cancer statistics and views of causes Science News Vol.115, No 2 (Jan.13 1979), p.23).”  It’s good that she provides a reference to her statement.  However, referencing a journal on genetics from 1979 is the equivalent of attempting to use the land-speed record from 1979 to justify your current preference of car.  The technology has advanced significantly, and genetic discoveries are lightyears ahead of where they were more than three decades ago.

“According to Dr Bruce Lipton (The Biology of Belief, 2008), gene disorders like Huntington’s chorea, beta thalassemia, cystic fibrosis, to name just a few, affect less than 2% of the population. This means the vast majority of the worlds population come into this world with genes that should enable the to live a happy and healthy life. He says a staggering 98% of diseases are lifestyle choices and therefore, thinking.”  Even if it’s true that Huntingtons, CF etc account for 2% of all illnesses, they account for only a tiny fraction of genetic disease.  And concluding that the remaining 98% must therefore be lifestyle related is overly simplistic.  It ignores the genetic influence on all other diseases, other congenital, and environmental causes of disease.  I will fully outline this point soon.

Similarly, “According to W.C Willett (balancing lifestyle and genomics research for disease prevention Science (296) p 695-698, 2002) only 5% of cancer and cardiovascular patients can attribute their disease to hereditary factors.”  Science is clear that genes play a significant role in the development of cardiovascular disease and most cancers, certainly greater than 5%.  Again, I will discuss this further soon.

“According to the American Institute of health, it has been estimated that 75 – 90% of all visits to primary care physicians are for stress related problems (http://www.stress.org/americas.htm). Some of the latest stress statistics causing illness as a result of toxic thinking can be found at: http://www.naturalwellnesscare.com/stress-statistics.html”  These websites not peer-reviewed, and both suffer from a blatant pro-stress bias.

You’ll also have to forgive my confusion, but Dr Leaf also wrote, “Dr H.F. Nijhout (Metaphors and the Role of Genes and Development, 1990) genes control biology and not the other way around.”  So is she saying that genes DO control development?


Influence Of Thought On Health

Dr Leaf has categorically stated that “75 to 98% of all illnesses are the result of our thought life” on a number of occasions.  She repeated the same statement in her most recent book so it is something she is confident in.  However, in order to be true, this fact must be consistent across the whole of humanity.

And yet, in a recent peer-reviewed publication, Mara et al state, “At any given time close to half of the urban populations of Africa, Asia, and Latin America have a disease associated with poor sanitation, hygiene, and water.” [2]  Bartram and Cairncross write that “While rarely discussed alongside the ‘big three’ attention-seekers of the international public health community—HIV/AIDS, tuberculosis, and malaria—one disease alone kills more young children each year than all three combined. It is diarrhoea, and the key to its control is hygiene, sanitation, and water.” [3]  Hunter et al state that, “diarrhoeal disease is the second most common contributor to the disease burden in developing countries (as measured by disability-adjusted life years [DALYs]), and poor-quality drinking water is an important risk factor for diarrhoea.” [4]

Toilets and clean running water have nothing to do with stress or thought.  We live in a society that essentially prevents more than half of our illnesses because of internal plumbing, with additional benefits from vaccination and population screening.  If thoughts have any effect on our health, they are artificially magnified by our clean water and sewerage systems.  Remove those factors and any effects of thought on our health disappear from significance.  Dr Leaf’s assertion that 75 to 98% of human illness is thought-related is a clear exaggeration.

Let me be clear – I understand the significance of stress on health and the economy, but it is not the cause of 75-98% of all illnesses.  I’m not sure if there is a similar study in the US, but the latest Australian data suggests that all psychological illness only counts for 8% of visits to Australian primary care physicians [5].

In terms of cancer, I don’t have time to exhaustively list every cancer but of the top four listed in the review “Cancer Statistics 2013” [6] , here are the articles that list the gene x environment interactions:

  1. PROSTATE – There are only two risk factors for prostate cancer, familial aggregation and ethnic origin. No dietary or environmental cause has yet been identified [7].  It is most likely caused by multiple genes at various loci [8].
  2. BREAST – Genes make up 25% of the risk factors for breast cancer, and significantly interacted with parity (number of children born) [9].
  3. LUNG/BRONCHUS – Lung cancer is almost exclusively linked to smoking, but nicotine addiction has a strong hereditary link (50-75% genetic susceptibility) [10].
  4. COLORECTUM – Approximately one third of colorectal cancer is genetically linked [11].

So the most common cancer is not linked to any environmental factors at all, and the others have genetic influences of 25% to more than 50%.  This is far from being 2% or 5% as Dr Leaf’s sources state.

Also in terms of heart disease, the INTERHEART trial [12] lists the following as significant risk factors, and I have listed the available gene x environment interaction studies that have been done on these too:

  1. HIGH CHOLESTEROL – Genetic susceptibility accounts for 40-60% of the risk for high cholesterol [13].
  2. DIABETES – Genetic factors account for 88% of the risk for type 1 diabetes [14].  There is a strong genetic component of the risk of type 2 diabetes with 62-70% being attributable to genetics [15, 16].
  3. SMOKING – nicotine addiction has a strong hereditary link (50-75% genetic susceptibility) [10].
  4. HYPERTENSION – While part of a much greater mix of variables, genetics are still thought to contribute between 30% and 50% to the risk of developing high blood pressure [17].

So again, while genes are a part of a complex system, it is clear from the most recent evidence that genetics account for about 50% of the risk for cardiovascular disease, which again is a marked difference between the figures that Dr Leaf is using to base her assertions on.

Atrial Natriuretic Peptide

I am aware of research that’s studied the anxiolytic properties of Atrial Natriuretic Peptide.  For example, Wiedemann et al [18] did a trial using ANP to truncate panic attacks.  However, these experiments were done on only nine subjects, and the panic attacks were induced by cholecystokinin.  As such, the numbers are too small to have any real meaning.  And the settling is completely artificial.  Just as CCK excretion does not cause us all to have panic attacks every time we eat, ANP does not provide anxiolysis in normal day to day situations.  Besides, if ANP were really effective at reducing anxiety, then why do people suffering from congestive cardiac failure, who have supraphysiological levels of circulating ANP [19] , also suffer from a higher rate of anxiety and panic disorders than the general population? [20]

The Heart As A Mini-Brain

As for Heartmath, they advance the notion of the heart being a mini-brain to give themselves credibility.  It’s really no different to an article that I read the other day from a group of gut researchers [21] – “‘The gut is really your second brain,’ Greenblatt said. ‘There are more neurons in the GI tract than anywhere else except the brain.’”  The heart as a mini-brain and the gut as a mini-brain are both figurative expressions.  Neither are meant to be taken literally.  I welcome Dr Leaf to tender any further evidence in support of her claim.

Hard-Wired For Optimism

As for being wired for optimism, the brain is likely pre-wired with a template for all actions and emotions, which is the theory of protoconsciousness [22].  Indeed, neonatal reflexes often reflect common motor patterns.  If this is true, then the brain is pre-wired for both optimism and love, but also fear.  This explains the broad role of the amygdala in emotional learning [23] including fear learning.  It also means that a neonate needs to develop both love and fear.

A recent paper showed that the corticosterone response required to learn fear is suppressed in the neonate to facilitate attachment, but with enough stress, the corticosterone levels build to the point where amygdala fear learning can commence [24].  The fear circuits are already present, only their development is suppressed.  Analysis of the cohort of children in the Bucharest Early Intervention Project showed that negative affect was the same for both groups.  However positive affect and emotional reactivity was significantly reduced in the institutionalised children [25].  If the brain is truly wired for optimism and only fear is learned, then positive emotional reactivity should be the same in both groups and the negative affect should be enhanced in the institutionalised cohort.  That the result is reversed confirms that neonates and infants require adequate stimulation of both fear and love pathways to grow into an emotionally robust child, because the brain is pre-wired for both but requires further stimulation for adequate development.

The Mind-Brain Link

If the mind controls the brain and not the other way around as Dr Leaf suggests, why do anti-depressant medications correct depression or anxiety disorders?  There is high-level evidence to show this to be true [26-28].  The same can be said for recent research to show that medications which enhance NDMA receptors have been shown to improve the extinction of fear in anxiety disorders such as panic disorder, OCD, Social Anxiety Disorder, and PTSD [29].

If the mind controls the brain and not the other way around as Dr Leaf suggests, why do some people with acquired brain injuries or brain tumours develop acute personality changes or thought disorders?  Dr Leaf has done PhD research on patients with closed head injuries and treated them in clinical settings according to her CV.  She must be familiar with this effect.

One can only conclude that there is a bi-directional effect between the brain and the stream of thought, which is at odds with Dr Leaf’s statement that the mind controls the brain and not the other way around.


One further thing.  Can you clarify which of Dr Leaf’s peer-reviewed articles have definitively shown the academic improvement in the cohort of 100,000 students, as you and your referee have stated?  And can you provide a list of articles which have cited Dr Leaf’s Geodesic Information Processing Model?  Google Scholar did not display any articles that had cited it, which must be an error on Google’s part.  If her theory is widely used as you say, it must have been extensively cited.

I understand that you are both busy, but I believe that I have documented a number of observations, backed by recent peer-reviewed scientific literature, which directly contradict Dr Leaf’s teaching.  I have not had a chance to touch on many, many other points of disagreement.

For the benefit of Dr Leaf’s followers, and for the scientific and Christian community at large, I would appreciate your response.

I would be grateful if you could respond to the points raised and the literature which supports it, rather than an Ad Hominem dismissal or further defense by association.

Dr C. Edward Pitt


1. Fowler, G., Evidence-based practice: Tools and techniques. Systems, settings, people: Workforce development challenges for the alcohol and other drugs field, 2001: 93-107.

2. Mara, D., et al., Sanitation and health. PLoS Med, 2010. 7(11): e1000363.

3. Bartram, J. and Cairncross, S., Hygiene, sanitation, and water: forgotten foundations of health. PLoS Med, 2010. 7(11): e1000367.

4. Hunter, P.R., et al., Water supply and health. PLoS Med, 2010. 7(11): e1000361.

5. FMRC. Public BEACH data. 2010  16JUL13]; Available from: <http://sydney.edu.au/medicine/fmrc/beach/data-reports/public&gt;.

6. Siegel, R., et al., Cancer statistics, 2013. CA Cancer J Clin, 2013. 63(1): 11-30.

7. Cussenot, O. and Valeri, A., Heterogeneity in genetic susceptibility to prostate cancer. Eur J Intern Med, 2001. 12(1): 11-6.

8. Alberti, C., Hereditary/familial versus sporadic prostate cancer: few indisputable genetic differences and many similar clinicopathological features. Eur Rev Med Pharmacol Sci, 2010. 14(1): 31-41.

9. Nickels, S., et al., Evidence of gene-environment interactions between common breast cancer susceptibility loci and established environmental risk factors. PLoS Genet, 2013. 9(3): e1003284.

10. Berrettini, W.H. and Doyle, G.A., The CHRNA5-A3-B4 gene cluster in nicotine addiction. Mol Psychiatry, 2012. 17(9): 856-66.

11. Hutter, C.M., et al., Characterization of gene-environment interactions for colorectal cancer susceptibility loci. Cancer Res, 2012. 72(8): 2036-44.

12. Yusuf, S., et al., Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet, 2004. 364(9438): 937-52.

13. Asselbergs, F.W., et al., Large-scale gene-centric meta-analysis across 32 studies identifies multiple lipid loci. Am J Hum Genet, 2012. 91(5): 823-38.

14. Wu, Y.L., et al., Risk factors and primary prevention trials for type 1 diabetes. Int J Biol Sci, 2013. 9(7): 666-79.

15. Ali, O., Genetics of type 2 diabetes. World J Diabetes, 2013. 4(4): 114-23.

16. Murea, M., et al., Genetic and environmental factors associated with type 2 diabetes and diabetic vascular complications. Rev Diabet Stud, 2012. 9(1): 6-22.

17. Kunes, J. and Zicha, J., The interaction of genetic and environmental factors in the etiology of hypertension. Physiol Res, 2009. 58 Suppl 2: S33-41.

18. Wiedemann, K., et al., Anxiolyticlike effects of atrial natriuretic peptide on cholecystokinin tetrapeptide-induced panic attacks: preliminary findings. Arch Gen Psychiatry, 2001. 58(4): 371-7.

19. Ronco, C., Fluid overload : diagnosis and management. Contributions to nephrology,. 2010, Basel Switzerland ; New York: Karger. viii, 243 p.

20. Riegel, B., et al., State of the science: promoting self-care in persons with heart failure: a scientific statement from the American Heart Association. Circulation, 2009. 120(12): 1141-63.

21. Arnold, C. Gut feelings: the future of psychiatry may be inside your stomach. 2013  [cited 2013 Aug 22]; Available from: http://www.theverge.com/2013/8/21/4595712/gut-feelings-the-future-of-psychiatry-may-be-inside-your-stomach.

22. Hobson, J.A., REM sleep and dreaming: towards a theory of protoconsciousness. Nat Rev Neurosci, 2009. 10(11): 803-13.

23. Dalgleish, T., The emotional brain. Nat Rev Neurosci, 2004. 5(7): 583-9.

24. Landers, M.S. and Sullivan, R.M., The development and neurobiology of infant attachment and fear. Dev Neurosci, 2012. 34(2-3): 101-14.

25. Bos, K., et al., Psychiatric outcomes in young children with a history of institutionalization. Harv Rev Psychiatry, 2011. 19(1): 15-24.

26. Arroll, B., et al., Antidepressants versus placebo for depression in primary care. Cochrane Database Syst Rev, 2009(3): CD007954.

27. Soomro, G.M., et al., Selective serotonin re-uptake inhibitors (SSRIs) versus placebo for obsessive compulsive disorder (OCD). Cochrane Database Syst Rev, 2008(1): CD001765.

28. Kapczinski, F., et al., Antidepressants for generalized anxiety disorder. Cochrane Database Syst Rev, 2003(2): CD003592.

29. Davis, M., NMDA receptors and fear extinction: implications for cognitive behavioral therapy. Dialogues Clin Neurosci, 2011. 13(4): 463-74.

Mac Leaf responds to “Dr Caroline Leaf – Serious Questions, Few Answers”

Mr Mac Leaf, the husband of Dr Caroline Leaf, kindly took the time to respond to my series of posts on the teachings of Dr Leaf at Kings Christian Centre, on the Gold Coast, Australia, earlier this month.  As I had intended, and as Mr Leaf requested, here is his reply, complete and unabridged.  My further response is posted here.

In the interests of healthy public debate, and encouraging people to make their own informed decisions on the teachings of Dr Leaf, any comments regarding the response of Mr Leaf or my reply are welcome provided they are constructive.

Hi Dr C. Pit,

It is a pity you did not seek to clarify the comments you have posted above with us before you posted them. We hope you allow our comments to be displayed so that your readers can make informed decisions and not to judge Dr Leaf as you have done without getting accurate information. By your comments it is obvious that you have not kept up to date with the latest Scientific research.

Dr Leaf can call herself a Cognitive Neuroscientist because of her field research (published in peer evaluated Journals) …see the Science articles in the media/downloads section at drleaf.com. If you require, we can also send letters from her peers in the field of Neuroscience

She also developed the Geodesic Information Processing model theory.

Yes she does read a lot as the field of Neuroscience is constantly evolving and one has to be as informed as possible.

Some research links re the correlation between illness and thought are presented in Dr Leaf’s November the 30th blog at drleaf.com…blog. There are many more statistic correlation research links.

Dr Leaf has listed references differently in the different books and has a full list of references in the ‘thought life’ section at drleaf.com. The references were listed simply in that book for the lay person. This is an accepted literary format for the lay person. Subsequent books have fuller references.

The mini brain in the heart research can be found at Heartmath.org

Heartmath and Dr Don Colbert both reference the effect of ANF

The wired for optimism bias research has been evidenced by various scientific researchers
For easy access to this research please see the Google links to TED talks and Time Magazine’s article.

Please send us your E-mail address so that we can send you further documentation.

My name is Dr Peter Amua-Quarshie and I am presently a full-time Adjunct Professor (lecturer) at the University of Wisconsin-Stout in Menomonie, Wisconsin. I have a B.Sc (Hons) in Medical Sciences (specializing in Neuropathology) and a Masters of Public Health (MPH), both degrees from the University of Leeds (UK). Additionally I have a medical degree (MB ChB) from the University of Ghana Medical School, Accra, Ghana, and a Master’s of Science (MS) in Behavioral and Neural Sciences from Rutgers University, Newark, New Jersey. I started teaching anatomy in the University of Leeds Medical School in 1996. I have taught Neurochemistry to graduate students and Neuroscience to undergraduates at Delaware State University and the University of Wisconsin respectively. I have known Dr. Caroline Leaf since 2006 and have worked closely with her since 2008 on various projects in the field of cognitive neuroscience.
Caroline Leaf received her training in Communication Pathology (BSC Logopaedics) at the University of Cape Town, South Africa. The University of Cape Town has produced many outstanding graduates, including Max Theiler, a Nobel Prize laureate in Physiology or Medicine and Christaan Barnard, the first person to successfully transplant a human heart. Caroline Leaf was a contemporary to the eminent neuroscientist Henry Markram, director of the Blue Brain Project and the new one billion Euro European Union Flagship Project, the Human Brain Project. As well having to study the cognition, she had to endure the rigor of the first 2 years of the medical course, in which she had to study neuroanatomy and neurophysiology. Dr. Leaf also holds a Master’s degree and PhD in Communication Pathology from the University of Pretoria, South Africa. In her Master’s degree her dissertation concentrated on cognitive neuroscience of Traumatic Brain Injury (Closed Head Injury). In developing her groundbreaking Geodesic Learning™ Theory (brain-compatible learning) in her ground breaking PhD thesis, she examined cognition and neurobiology of thinking. The Geodesic Learning™ Theory has been implemented among approximately 100,000 students in South Africa with great success. I have personally helped implement her Geodesic Learning™ Theory in a School District in the USA and was able to demonstrate quantitative improvement in scholastics across the board among the students. She is widely published in journal, book, DVD, television and the internet in the field of cognitive neuroscience in South Africa, USA and other parts of the world.
I have discussed neuroscientific subjects with her for multiple hours many times and have been thoroughly impressed with her knowledge and insight in neurobiology. However what really thrills me is revelation God gives her about the brain. She is an example to me of a neuroscientist who glorifies God in her pursuit of understanding the brain, and who is able to demonstrate that we are truly fearfully and wonderfully made (Psalm 139:14).


Since 1985, Dr Caroline Leaf, a Communication Pathologist and Audiologist, has worked in the area of Cognitive Neuroscience. She holds a Bsc Logopaedics with focus on in Neuroscience, Neuronanatomy and anatomy, Communication Pathology, Psychology, linguistics and audiology) , Masters in Communication Pathology She specialized in Traumatic Brain Injury and PhD in Communication Pathology (TBI) and Learning Disabilities focusing specifically on the Science and neuroscience of Thought as it pertains to thinking and learning. She developed a Cognitive Neuroscientific theory called the Geodesic Information Processing Theory for her PhD research and did some of the initial research back in the 1990’s showing how using non-traditional techniques, based on neuroscientific principles of neuroplasticity and neuropsychological principles, that the mind can change the brain and can effect behavioural change as seen academically, behaviorally and emotionally. A large part of her research in recent years has been to link scientific principles with scripture showing how science is catching up with the bible.

She applied the findings of her statistically proven research in clinical practice for nearly 20 years and now lectures and preaches around the world on these topics. She is a prolific author of many books, articles and scientific articles. She has been a featured guest of Enjoying Everyday Life with Joyce Meyer, and LIFE TODAY with James and Betty Robison, Marilyn Hickey, Sid Roth and TBN Doctor to Doctor, amongst many others. She has her own show on TBN called Switch on Your Brain.

Her passion is to help people see the link between science and scripture as a tangible way of controlling their thoughts and emotions, learning how to think and learn and finding their sense of purpose in life.

Caroline and her husband, Mac, live in Dallas, Texas with their four children.

Dr Leaf’s Qualifications

Web page: http://www.drleaf.com has my full qualifications and links to the Universities where I studied

Dr Leaf’s Reference list

1. Leaf, C.M. 1985. “Mind Mapping as a Therapeutic Intervention Technique”. Unpublished workshop manual.

2. Leaf, C.M. 1989. “Mind Mapping as a Therapeutic Technique” in Communiphon, South African Speech-Language-Hearing Association, 296, pp. 11-15.

3. Leaf, C.M. 1990. “Teaching Children to Make the Most of Their Minds: Mind Mapping” in Journal for Technical and Vocational Education in South Africa, 121, pp. 11-13.

4. Leaf, C.M. 1990. “Mind Mapping: A Therapeutic Technique for Closed Head Injury”. Masters Dissertation, University of Pretoria.

5. Leaf, C.M. 1992. “Evaluation and Remediation of High School Children’s Problems Using the Mind Mapping Therapeutic Approach” in Remedial Teaching, Unisa, 7/8, September 1992.

6. Leaf, C.M., Uys, I.C. and Louw, B. 1992. “The Mind Mapping Approach(MMA): A Culture and Language-Free Technique” in The South African Journal of Communication Disorders, Vol. 40, pp. 35-43.

7. Leaf, C.M. 1993. “The Mind Mapping Approach (MMA): Open the Door to Your Brain Power; Learn How to Learn” in Transvaal Association of Educators Journal (TAT).

8. Leaf, C.M. 1997. “The Mind Mapping Approach: A Model and Framework for Geodesic Learning”. Unpublished D.Phil Dissertation, University of Pretoria.

9. Leaf, C.M. 1997. “The Development of a Model for Geodesic Learning: The Geodesic Information Processing Model” in The South African Journal of Communication Disorders, Vol. 44, pp. 53-70.

10. Leaf, C.M. 1997. “The Move from Institution Based Rehabilitation (IBR) to Community Based Rehabilitation (CBR): A Paradigm Shift” in Therapy Africa, 1 (1) August 1997, p. 4.

11. Leaf, C.M. 1997. ‘”An Altered Perception of Learning: Geodesic Learning” in Therapy Africa, 1 (2), October 1997, p. 7.

12. Leaf, C.M., Uys, I. and Louw. B., 1997. “The Development of a Model for Geodesic Learning: the Geodesic Information Processing Model” in The South African Journal For Communication Disorders, 44.

13. Leaf, C.M. 1998. “An Altered Perception of Learning: Geodesic Learning: Part 2” in Therapy Africa, 2 (1), January/February 1998, p. 4.

14. Leaf, C.M., Uys, I.C. and Louw, B. 1998. “An Alternative Non-Traditional Approach to Learning: The Metacognitive-Mapping Approach” in The South African Journal of Communication Disorders, 45, pp. 87-102.

15. Leaf. C.M. 2002. Switch on Your Brain with the Metacognitive-Mapping Approach. Truth Publishing.

16. Leaf, C.M. 2005. Switch on Your Brain. Understand Your Unique Intelligence Profile and Maximize Your Potential. Tafelberg, Cape Town, SA

17. Leaf, C.M. 2008. Switch on Your Brain 5 Step Learning Process. Switch on Your Brain USA, Dallas.

18. Leaf, C.M. 2007. Who Switched Off My Brain? Controlling Toxic Thoughts and Emotions. Switch on Your Brain USA, Dallas.

19. Leaf, C.M. 2007. “Who Switched Off My Brain? Controlling Toxic Thoughts and Emotions”. DVD series. Switch on Your Brain, Johannesburg, SA.

20. Leaf, C.M., Copeland M. & Maccaro, J. 2007. “Your Body His temple. God’s Plan for Achieving Emotional Wholeness”. DVD series. Life Outreach International, Dallas.

The end of the sugar obsession?

I was flicking through Facebook this evening as I usually do, hoping to vicariously share someone else’s joy in life, when I came across this little tidbit, “You know what? Don’t quit sugar.”

The link was to a blog on mamamia.com.au (http://www.mamamia.com.au/health-wellbeing/you-know-what-dont-quit-sugar/) which asked if the tide of the quit sugar obsession was starting to recede.  It discussed the recent post of Sarah Wilson, a journalist for Fairfax and the author of several books on quitting sugar, which have become immensely popular by tagging on the coat-tails of David Gillespie’s “Sweet Poison” books.

In her blog, Wilson confessed to a barely forgivable sin of giving in to peer pressure and eating two chocolate croissants, then emotionally self-flagellating for the rest of the day.  That the symptoms that she described fitted nicely into the category of an anxiety neurosis didn’t seem to register with Wilson, who carried on like she had ingested a large goblet of hemlock.

Credit to the mammamia team who published some of the comments of real nutritionists like Cassie Platt, and eating-disorder counsellors like Paula Kotowitz, who said,

“Being harsh on ourselves, not only does not help, but makes us feel so much worse in the long run because it deconstructs our sense of self and causes us to beat up on ourselves. Isn’t it possible that there is a happy medium in there somewhere? It’s not crack. Just food.”

Platt, who is about to release a book titled, “Don’t Quit Sugar”, says,

“Your food choices should be based on biological and metabolic needs. What we eat should fuel our cells, facilitate growth, repair and reproduction and, most importantly, enable your body to function at its very best.”

Platt said that she has previously tried removing sugar from her diet and that she had to “claw” her way back to health.

The mamamia writing team summed up by saying,

“The benefits of reducing sugar intake are widely accepted in the scientific community but the idea of avoiding it altogether remains an issue of serious contention. And the possibility that these sorts of diet programs can mask dangerous eating disorders, is particularly worrying.”

They asked the question, “Has the sugar-quitting backlash begun?”  For the love of all things sacred, I seriously hope so.

About a month ago I wrote a piece about the quit sugar fad, and posted evidence that eating an extremely low carbohydrate diet is no better than eating a low fat diet, because it’s calories, not sugar, that makes all the difference to weight gain or loss.

A balanced, low calorie diet has been pushed by nutritionists and doctors ad nauseum for decades, but consistently neglecting to use words like “poison”, “toxin” or “death” has meant that the message is nowhere near as stimulating as the current whim.

Is it possible to have your cake and eat it too?  Absolutely.  My hero of nutritional science, Dr Rosemary Stanton, spoke at a Brisbane conference a couple of years ago and succinctly debunked Gillespie, Wilson and their ilk.  She also explained the concept of feasting, the long forgotten art form of having exceptionally good food once in a while, and enjoy it with friends, rather than eating substandard food every day by yourself, which is the modern trend.

Rather than gorging on sugar every day to compensate for your loneliness and despair, Dr Stanton advocated a diet high in vegetables and little or no processed food on a daily basis.  But then once a month or two, she advised to enjoy your favourite food, no matter what it might happen to be – cheesecake, ice cream, chocolate croissants – anything you like.  The only rules were to make sure that it is really good quality, the best that you can afford, so that it is worth savouring and looking forward to next time, and enjoy it with friends, since the social aspects of the food we eat are as important as the nutritional value.  Sage advice from someone who has been researching nutrition for longer than I’ve been alive.

I’m sure that by now, Sarah Wilson will have got over her sugar intoxication.  She may not have enjoyed it, but I hope that ends up being a pivotal moment in correcting the imbalance in our relationship to sugar, and living by the facts, not the latest fad.

Autism Series 2013 – Part 2: The History Of Autism

“We can chart our future clearly and wisely only when we know the path which has led to the present.” Adlai E. Stevenson

I always thought history was boring, and I must admit, If you want to put me to sleep, start reading early Australian history to me. “Convicts … first fleet … zzzzzz.”

But as Stevenson wrote, the key to the future is the past. With autism, I don’t want to see a future as checkered as its past. In this series of essays, I want to help our community see a future in which autism is recognised and appreciated for its strengths. To properly lay the groundwork, I want to look at the history of autism. This will help provide context for the current understanding of autism, which will then give a framework for understanding the autistic person, and for a glimpse into the future as new research unfolds.

The autistic spectrum has been present for as long as humans have. But to our knowledge, one of the first specific descriptions of someone who met the characteristics of the autistic spectrum was in the mid 1700’s. In 1747, Hugh Blair was brought before a local court to defend his mental capacity to contract a marriage. Blair’s younger brother successfully had the marriage annulled to gain Blair’s share of inheritance. The recorded testimony describes Blair as having the classic characteristics of autism, although the court described him at the time as lacking common sense and being afflicted with a “silent madness”.[1]

Isolated case reports appeared sporadically in medical journals. John Haslam reported a case in 1809, although with modern interpretation, the child probably had post-encephalitis brain damage rather than true autism. Henry Maudsley described a case of a 13 year old boy with Aspergers traits in 1879. There were no other reports of children with autism in the early literature, although at the turn of the 19th century, Jean Itard reported on the case of an abandoned child found roaming in the woods like a wild animal. This child, called Victor, displayed many features of autism, although he may have simply had a speech disorder. Either diagnosis was obscured by the effects of severe social isolation.[1]

Others described syndromes which shared autistic features, but without describing autism itself. The names given to each syndrome reveals how autistic features were regarded in the 19th century: Dementia Infantalis, Dementia Praecocissima, Primitive Catatonia of Idiocy.[1]

Around 1910, Eugen Bleuger was a Swiss psychiatrist who was researching schizophrenic adults (and as an aside, Bleuger was the person to first use the term ‘schizophrenia’). Bleuger used the term ‘autismus’ to refer to a particular sub group of patients with schizophrenia, from the Greek word “autos,” meaning “self”, describing a person removed from social interaction, hence, “an isolated self.”[2]

But it wasn’t until the 1940’s that the modern account of autism was articulated, when two psychiatrists in different parts of the world first documented a handful of cases. Leo Kanner documented eleven children who, while having variable presentations, all shared the same pattern of an inability to relate to people, a failure to develop speech or an abnormal use of language, strange responses to objects and events, excellent rote memory, and an obsession with repetition and sameness[3].

Kanner thought that the condition, which he labelled ‘infantile autism’, was a psychosis[1] – in the same family of disorders as schizophrenia, although separate to schizophrenia itself[2]. He also observed a cold, distant or anti-social nature of the parents relationship towards the child or the other parent. He thought this may have contributed (although he added that the traits of the condition were seen in very early development, before the parents relationship had time to make an impact)[3]. True to the influence of Freud on early 20th century psychiatry, Kanner said of the repetitive or stereotyped movements of autistic children, “These actions and the accompanying ecstatic fervor strongly indicate the presence of masturbatory orgastic gratification.”[3]

Despite the otherwise reserved, cautious discussion of possible causes of this disorder, the link with schizophrenia and “refrigerator mothers” took hold in professional and lay communities alike. In the 1960s and 70s, treatments for autism focused on medications such as LSD, electric shock, and behavioral change techniques involving pain and punishment. During the 1980s and 90s, the role of behavioral therapy and the use of highly controlled learning environments emerged as the primary treatments for many forms of autism and related conditions.[2]

Unbeknown to Kanner, at the same time as his theory of ‘infantile autism’ was published in an English-language journal, a German paediatrician called Hans Asperger published a descriptive paper of four boys in a German language journal. They all shared similar characteristics to the descriptions of Kanner’s children, but were functioning at a higher level. They shared some aggression, a high pitched voice, adult-like choice of words, clumsiness, irritated response to affection, vacant gaze, verbal oddities, prodigious ability with arithmetic and abrupt mood swings. Asperger was the first to propose that these traits were the extreme variant of male intelligence[4].

But the full impact of Asperger wasn’t felt until 1981, when British psychiatrist Lorna Wing translated Aspergers original paper into English. By this time, autism had become a disorder of its own according to the DSM-III, the gold-standard reference of psychiatric diagnosis, but it was still largely defined by the trait of profound deficit. Aspergers description of a ‘high-functioning’ form of autism resonated amongst the autism community, and a diagnosis of Aspergers Syndrome became formally recognised in the early 1990’s with the publication of the DSM-IV.

The most recent history of autism comes in two parts. The first was the revision of the DSM-IV. For the first time, rather than two separate diagnoses, Autism and Aspergers have been linked together as a spectrum and collectively known as the Autism Spectrum Disorders (although autism self-advocates prefer the term ‘conditions’ to ‘disorders’).

The second part is a highly controversial chapter that will stain the history of autism research and scientific confidence, into the next few decades. Chris Mooney, in a piece for Discover Magazine, sums it up nicely:

“The decade long vaccine-autism saga began in 1998, when British gastroenterologist Andrew Wakefield and his colleagues published evidence in The Lancet suggesting they had tracked down a shocking cause of autism. Examining the digestive tracts of 12 children with behavioral disorders, nine of them autistic, the researchers found intestinal inflammation, which they pinned on the MMR (measles, mumps, and rubella) vaccine. Wakefield had a specific theory of how the MMR shot could trigger autism: The upset intestines, he conjectured, let toxins loose in the bloodstream, which then traveled to the brain. The vaccine was, in this view, effectively a poison.”[5]

Inflamed by a post-modern distrust of science and a faded memory of what wild-type infectious diseases did to children, the findings swept through the internet and social media and lead to a fall in vaccination rates (from about 95% to below 80% at its lowest)[6].

But the wise words, “Be sure your sins will find you out”, still hold true, even in modern science. In 2010, Wakefield was found guilty of Serious Professional Misconduct by the British General Medical Council, and was struck off the register of medical practitioners in the UK. In the longest ever hearing into such allegations, the GMC considered his conduct surrounding the research project, the medical treatment of his child subjects, and his failure to disclose his various conflicts of interest to be dishonest and professionally and clinically unethical[7]. There is evidence that he also selectively chose his subjects to confound the results, misrepresented the time course of their symptoms related to the vaccinations, misrepresented their diagnosis of autism, and altered the reports of their bowel tests[8, 9].

For the record, this isn’t a comment on the science of Wakefield’s rise and fall, but the history. I am not suggesting that the proposed autism/vaccination link should be discounted solely on the basis of Wakefield’s scientific fraud. Rigorous science has already done that. The science for and against the proposed link between autism and vaccinations deserves special attention, and will be discussed in a future post. Rather, lessons need to be learned from what is one of the most destructive cons in the recent history of medicine.

The losers of this hoax are twofold. Thousands of children have unnecessarily suffered from preventable infectious disease because of a fear of vaccines that has turned out to be unfounded, and those who actually have autism miss out on actual funding because it was syphoned off into Wakefield’s pockets and into research disproving his rancid theory. As the editorial in the BMJ stated, “But perhaps as important as the scare’s effect on infectious disease is the energy, emotion, and money that have been diverted away from efforts to understand the real causes of autism and how to help children and families who live with it.”[6]

As with all good history, there are lessons for the future. Autism is still largely misunderstood. The vacuum of definitive scientific knowledge is slowly being filled, gradually empowering people with autism and the people that interact with them to truly understand and communicate. Each breakthrough and revision of the diagnosis has lead to more sophisticated and more humane ways of living with autism. But there is still a need for caution – people will use the gaps in knowledge and the pervasive distress that can come from the diagnosis, to manipulate and exploit for their own ends.

I’ll continue with the series in the next week or so, looking at the modern “epidemic” of autism.


1. Wolff, S., The history of autism. Eur Child Adolesc Psychiatry, 2004. 13(4): 201-8.
2. WebMD: The history of autism. 2013  [cited 2013 August 14]; Available from: http://www.webmd.com/brain/autism/history-of-autism.
3. Kanner, L., Autistic disturbances of affective contact. Acta Paedopsychiatr, 1968. 35(4): 100-36.
4. Draaisma, D., Stereotypes of autism. Philos Trans R Soc Lond B Biol Sci, 2009. 364(1522): 1475-80.
5. Mooney, C., Why Does the Vaccine/Autism Controversy Live On?, in Discover2009, Kalmbach Publishing Co: Waukesha, WI.
6. Godlee, F., et al., Wakefield’s article linking MMR vaccine and autism was fraudulent. BMJ, 2011. 342: c7452.
7. General Medical Council. Andrew Wakefield: determination of serious professional misconduct, 24 May 2010. http://www.gmc-uk.org/Wakefield_SPM_and_SANCTION.pdf_32595267.pdf
8. Deer, B., How the case against the MMR vaccine was fixed. BMJ, 2011. 342: c5347.
9. Deer, B., More secrets of the MMR scare. Who saw the “histological findings”? BMJ, 2011. 343: d7892.

Autism Series 2013; Part 1 – Why it matters.

What do you think of when you think about autism?  Is it a TV character like Jake, from Kiefer Sutherland’s recent series ‘Touch’, or perhaps Sheldon from ‘The Big Bang Theory’?  Or is it a movie character like the savant that Dustin Hoffman played in ‘Rain Man’? They are common stereotypes, but they only depict a tiny fraction of the autism that is all around us every day.  Chances are, you would run into people every day who have autism.  Would you be able to pick them?

The current point prevalence rate of autism is given by various international health bodies including the World Health Organization, as one person in a hundred.  With a prevalence of one percent of the population as having autism, you would think it would be better known, better dealt with by teachers, better handled by public officials, better screened and managed by health workers, and better resourced in terms of assistance to families and in terms of research dollars.

But while funding and recognition are important, the greatest impact that the lack of autism awareness has is the human cost.  It is the cost that can’t be measured in terms of dollars, caused by the maligned stigma that having autism brings.

Autism at the less severe end, what used  to be called ‘high functioning’ autism, or what I prefer to classify as (the now unofficial diagnosis of) Aspergers Syndrome, doesn’t make a person look that much different on the outside.  But it makes their behaviour somewhat odd to everyone else.  They have quirks.  They have strange mannerisms.  They have rigid ways of doing things.  They have very narrow interests.  They misread social cues.

“Normal” people don’t like odd.  Especially children.  If you don’t fit in to their particular group-think view of the world, their intolerant tormenting can be merciless and unrelenting.  Some people never grow up though, and many adults with autism can be marginalised by their adult peers. Every barb, joke and isolating experience eroding at the soul of a person with autism until there is nothing left.

This is the most destructive of all. It is death by a thousand insults.

I am writing this series of blogs because I want to help assist in whatever way I can to reduce the ignorance surrounding autism.  There is still so much ignorance out there – simple ignorance because the message is still diffusing through our social networks, and  obstinate ignorance, by people who use pseudoscientific scare mongering to promote their views, or promote bogus treatments for the sole purpose of taking advantage of the desperation of some of those who live with autism.

No matter which form of ignorance is out there, ignorance is ignorance and it does the same damage.  It needs to be stopped.

When I was a little boy, I was odd.  It took me a while before I started talking.  I had an obsession with vacuum cleaners and watches.  I was the misfit, or the loner.  I was incessantly bullied in the latter half of primary school and almost all the way through high school.  I didn’t want to go out and be with large groups of other kids.  My parents made me go to marshall arts training, cub scouts, church groups and school holiday excursions.

I hated those social outings.  I had huge anxiety being in these large groups.  Even when I wasn’t being mocked or belittled, I still felt anxious because I didn’t naturally fit in with the other kids.  The leaders of the group would go out of their way to include me but that had the opposite effect of highlighting how much of a social misfit I was.  The anxiety was disabling when I was in middle high school.

Thankfully I was smart, mainly in maths and science.  Academic achievement was my only positive, so I took refuge in studying.  I graduated in the top percentile in my state, and made it into medical school.  I did a whole medical degree, five years in hospitals including several in subspecialty paediatrics, and a fellowship in General Practice, and another eight years of GP experience, before my son was diagnosed as being on the autistic spectrum.

Despite years of medical training, It’s only been since my son’s diagnosis that I have been realising just how much of my quirky behaviour and social dysfunction was due to the fact that I’m on the spectrum too.  All those years, I thought I was retarded, socially incompetent, a freak.  All those years, I was bullied, harassed and made to think I was stupid, just because I didn’t naturally understand the unspoken social codes , but no one explained them to me.

That’s nearly forty years of living with self-doubt, low self-esteem, low self-confidence, and various mental health issues, because I never knew, because no one else knew, because of ignorance and intolerance.

So it stings when I hear people spread mistruths about ASD, and it pains me when the mistruths are spread by people who should know better.  It makes me mad when the mistruths come from self-titled ‘experts’.

I don’t want my son going through the same stigma and denigration, or anyone else on the spectrum for that matter.  The truth about autism – what it is, what it is caused by, and what strengths autism bestows, need to hold sway so that death by a thousand insults is no longer tolerable in our progressive society.

I will publish further blog posts over the coming days to weeks on what autism is, on why it seems to be increasing, and the latest scientific evidence on what autism may be caused by.  I will devote a whole blog (or two) to the misinformation surrounding vaccines and autism.  So stay tuned.

Dr Caroline Leaf – Serious questions, few answers (Part 3) – “Flirting with heresy”

Following on from the last 2 posts discussing the various teaching points of Dr Caroline Leaf at Kings Christian Church, here is my final post on the points that she raised.  Tonight, I conclude by proposing that in equating ‘toxic’ thoughts with sin, she seriously weakens her own argument, or she flirts with heresy.


Probably the most disturbing of all she discussed was her point blank statement that, “Toxic thoughts are sin.”

This is an astounding claim, and it was said in such an off-handed manner. It was like she threw a grenade and calmly moved on. Her claim not only has psychological ramifications, but deep theological connotations.

Her statement has the effect of ADDING to the stress response of her audience. Indeed, it sets up a feedback loop of self-perpetualising existential distress – the spiritual struggle switch. Crum et al (2013) showed that negatively framing the concept of stress leads to an increase in the subjects stress response. What could be more stressing that telling a christian that they have sinned every time that have had a persistent stress?  More stress is then equated with more ‘sin’ which then gives rise to even more stress. And so the cycle continues.

She then attempted to redeem her statement by declaring that we can transcend the guilt from the sin of stress, because her 21-day brain detox program would fix it. But on the surface, it seems an arbitrary premise. Inducing guilt to then offer to fix it is like a supermarket marking up a price so they can claim to offer a discount when they reduce it again.

More importantly though, in making the link between stress and sin, she brings herself undone. She either unravels her entire argument, or she flirts with heresy. Because if a thought process which results in prolonged or severe fear/stress is a sin, then Jesus himself sinned.

In the Garden of Gethsemane, the gospels record that Jesus, the spotless lamb of God, about to be crucified for the sins of all mankind, was “overwhelmed with sorrow to the point of death” (Mark 14:34, Matthew 26:38), and became so distressed by the ordeal he was about to endure that he literally sweat drops of blood (Luke 22:44).

Where do you think Jesus was on the stress spectrum according to those accounts? I’d wager that it wasn’t “healthy stress”.Rev Bob Deffinbaugh wrote that,

“Jesus spent what appears to be at least three agonizing hours in prayer.” He also noted that, “Never before have we seen Jesus so emotionally distraught. He has faced a raging storm on the Sea of Galilee, totally composed and unruffled. He has faced demonic opposition, satanic temptation, and the grilling of Jerusalem’s religious leaders, with total composure. But here in the Garden, the disciples must have been greatly distressed by what (little) they saw. Here, Jesus cast Himself to the ground, agonizing in prayer.” (https://bible.org/seriespage/garden-gethsemane-luke-2239-46)

There is no other way to explain it – Jesus suffered severe and prolonged mental anguish to the point that it had physical effects. By Dr Leaf’s definition (Leaf 2009, p19), Jesus had “toxic” thoughts. So the crux is: either toxic thoughts and emotions are sinful, in which case Jesus was a sinner and our salvation is invalid, or toxic thoughts and emotions are not sinful, which directly contradicts her teaching.

There is at least one further example from the life of Jesus that significantly weakens Dr Leafs definition of ‘toxic’ thoughts. In her book, Dr Leaf states, “hostility and rage are at the top of the list of toxic emotions”, and that “Stress is the direct result of toxic thinking.” (Leaf 2009, p29-30)

In John 2:13-17, it says, “When it was almost time for the Jewish Passover, Jesus went up to Jerusalem. In the temple courts he found people selling cattle, sheep and doves, and others sitting at tables exchanging money. So he made a whip out of cords, and drove all from the temple courts, both sheep and cattle; he scattered the coins of the money changers and overturned their tables. To those who sold doves he said, “Get these out of here! Stop turning my Father’s house into a market!” His disciples remembered that it is written: “Zeal for your house will consume me.”

So Jesus saw the sellers and the money exchangers, then in a pre-meditated way, took small cords and fashioned a whip out of them, then proceeded to use that whip to violently and aggressively overturn the tables of the merchants and spill the money of the money changers. John adds a post-script – “Zeal for your house will consume me.”  So Jesus wasn’t mincing words. He drove them out of the temple in a rage.

Again, was Jesus acting in sin?  Of course not.  Instead, perhaps God has designed normal human beings to experience rage, anger and stress – emotions that are not curses passed down in genetic material and are not learned behaviours as a result of our sin nature.

Further, God himself displayed anger.  God also made us in his image, and in his likeness. Dr Leaf stated that we were designed to function in optimism and love, and again, negative emotions like anger and fear are learnt from living in sin. Yet it is interesting that God the Father regularly kindled his wrath, and smote Israelites or their enemies (Numbers 11:33, Deuteronomy 11:16-17, and in 2 Kings 23:25-27, “Notwithstanding the Lord turned not from the fierceness of his great wrath, wherewith his anger was kindled against Judah, because of all the provocations that Manasseh had provoked him withal.”)

If God regularly displayed anger throughout the Old Testament, and Jesus displayed it in the New Testament, then anger and rage can not be the perversion of God’s ultimate design as Dr Leaf proposes.

Therefore, ‘toxic’ thought is NOT sin, because Jesus suffered prolonged mental stress and anguish and he did not sin.  Emotions that are deemed to be toxic by Dr Leaf and her definition are not toxic, since both God and Jesus displayed them and they did not and do not sin. Such a suggestion is incongruent with the Christian faith.

We were made in the image of God, so therefore we mirror all the emotions of God, which includes anger.  This shows that Dr Leaf’s proposals and the assumptions on which they are based, are incongruent with a logical interpretation of scripture.

In conclusion, Dr Leaf has been gathering quite a following.  From the pulpit at least, her claims of evidence of studies from peer-reviewed sources have been lacking. From what I saw on Sunday last, her reputation is excessive, her arguments unsupported and her theology is questionable at best, dangerous at worst.

Personally, I would welcome Dr Leaf’s response to these posts.  I have written these posts over a few days from her teaching at one church, so perhaps I have misunderstood her.  I have not been able to go through all of her books in such a short time, so she may have references to her teaching.  But she needs to clarify each question that I’ve raised and respond with current peer-reviewed science and sound theological resources.


Crum, A. J., P. Salovey and S. Achor (2013). “Rethinking stress: the role of mindsets in determining the stress response.” J Pers Soc Psychol 104(4): 716-733.

Karatsoreos, I. N. and B. S. McEwen (2011). “Psychobiological allostasis: resistance, resilience and vulnerability.” Trends Cogn Sci 15(12): 576-584.

Leaf, C. (2009). Who Switched Off My Brain? Controlling toxic thoughts and emotions. Southlake, TX, USA, Inprov, Ltd.

Dr Caroline Leaf – Serious questions, few answers (Part 2)

Yesterday I published the first part of an essay discussing the presentation of Dr Caroline Leaf, Audiologist, Communication Pathologist, and self-titled cognitive neuroscientist, at Kings Christian Church, Gold Coast.

Tonight I want to continue dissecting some of the more pertinent statements that she made, including her view of the mind-brain connection, a smattering of smaller issues, her over-reliance on case studies, and her opinion on the cause and treatment of ADHD.

Tomorrow I will publish the last, and most important part of my essay – That Dr Leaf believes that ‘toxic’ thoughts are sinful, and why this single statement unravels her most fundamental premise.


A large part of her sermon was based on her next premise, that the mind changes the brain, and not the other way around. That is half true. The mind influences the brain, and how we think will have effects on neural pathways within the brain. But for a cognitive neuroscientist to state that the brain does not influence the mind is somewhat concerning.

There are several reasons why her assertion is deeply flawed. For starters, where else does the mind or thought come from other than our neural networks? Thought is built on our neural connections. To say that the brain does not influence thought is like saying that the foundation of a building doesn’t influence the bricks.

There are clinical reasons as well. These come from a few areas – firstly the research that showed that newborn babies (who do not have thought like we have thoughts) are pre-wired for emotions which are refined as we learn. There is no time for neonates to have enough stimulation to form those emotions and reactions if it was from our mind.

Secondly, people with brain injuries or tumours can have personality or mood changes. The most famous was a man in the 1800’s called Phineas Gage, who on 13 September 1848 was packing explosives into rock with a tamping iron (a long, tapered, smooth crow-bar). History says that the explosives sent the tamping iron through his left face and skull, taking a fair chunk of his frontal lobe with it. Depending on who you believe, Gage’s personality changed after his physical recovery, reportedly from a moral, respectful man into a cursing, angry one (Kihlstrom 2010). Some reports of his story were that Gage made an almost full recovery, but assuming that some of the historical record is true, changes to his brain changed his mental function, ie: his thoughts.

Further, I have personally seen two patients with personality changes secondary to brain tumours. The first was a woman in her late 20’s who had six months of worsening anxiety, who did not seek help despite my referrals, until she had a seizure and the diagnosis was made. Then there was the sad case of a girl in her pre-teens who had only two weeks of rapidly escalating sullenness then aggression then violence. Her parents initially thought she was moody, and when they brought her into the Emergency Department they thought she was perhaps in the middle of a psychotic episode. It turned out that she had a very aggressive tumour near her frontal lobe.

It is clear from these cases, and from a basic understanding of the concept of thought, that changes to the brain result in changes to thoughts and the mind, and vice versa.


If I had the time I would like to look at many others issues that she raised, but this isn’t a book. Suffice it to say that she claimed that stress prunes our “thought trees” although the evidence is only in animal models and only related to severe stress (Karatsoreos and McEwen 2011). She also stated that EVERY thought we EVER have is stored in ALL of our cells (so some random fibroblast in my big toe is somehow affected by my thought about tonights dinner), and that ALL our thoughts are stored in our gametes (our sperm and eggs) and are passed down to our 4th generation (but packed, like in a metaphysical zip-lock bag, and only opened if we choose to have the same thoughts.) And here I was thinking that nurture had something to do with learned behaviour.


She also claimed that 55-70% of ASD/ADHD cases are over-referred and the problem is in educational modeling. This one made me mad.

Not even professorial level researchers know exactly what’s going on in ASD/ADHD, so her statement is a brave one to make, especially without referencing her evidence.

She then espoused the party line of ADHD ignorance – that Ritalin is evil and all you need to do is stop their sugar intake and feed them organic foods and give them supplements. Ritalin isn’t perfect, to be sure, but it is the most effective treatment that’s currently available. If dietary measures and educational measures were effective, then ritalin wouldn’t be prescribed. I have never met a parent that has wanted their child on ritalin. Most of them have tried educational/psychological measures or dietary controls first. The reason why ritalin is prescribed is because dietary and psychological interventions on their own do not adequately control the symptoms, or fail altogether.

To confirm that I’m not just having a rant, there is published scientific literature to back me up. In their recently published meta-analysis, Nigg et al (2012) state, “An estimated 8% of children with ADHD may have symptoms related to synthetic food colors.” Eight percent. That’s all! That’s ninty-two percent of children with ADHD (real ADHD, not just rambunctious children with lots of energy) DID NOT have symptoms due to food colourings. Their conclusions: “A restriction diet benefits some children with ADHD. Effects of food colors were notable but susceptible to publication bias or were derived from small, nongeneralizable samples.” In terms of sugar, Kim and Chang (2011) note that, “children who consumed less sugar from fruit snacks or whose vitamin C intake was less than RI was at increased risks for ADHD (P < 0.05).” (emphasis added) The study was only of about 100 children, but the result was statistically significant. It wasn’t a chance effect.

The misinformation she stated as fact from the pulpit promotes scare-mongering and ignorance throughout the church, which has flow on effects. Church members with children with ADHD or ASD will avoid standard medical treatment on Dr Leaf’s advice. When her treatments fail in the majority of cases, those parents will either live with unnecessarily heightened stress because of their child’s poorly controlled condition, or the guilt of using ritalin, all the while believing that they are ruining their childs brain.

This also places the hosting church in a bind. Do they stand behind their guest speaker, or do they support the advice of the medical community? Is their duty of care to the reputation of the guest speaker or to the congregation under their protection? What would happen if Dr Leaf’s advice lead to the death or disability of a person in their congregation? Would they be libel?


Dr Leaf also told a lot of stories of how everyone afflicted came to her and how she healed them all. If you took her at face value, she would have you believe that people with ASD, ADHD, anorexia, OCD, depression etc, just needed a glimpse of their self-worth and their inner gift and they would be cured. While her stories were inspirational, the world of scientific research demands more. If Dr Leaf’s insights are worth more than the hot air she produces when espousing them, then they should be put to the wider research community so they can pass through the fire of peer review. If peer review prove her insights to be valid, I would be happy to apply them and promote them.

Tomorrow, I will publish the last, and probably the most important part of my essay – that Dr Leaf believes that ‘toxic’ thoughts are sinful, and why this single statement unravels her most fundamental premise.


Crum, A. J., P. Salovey and S. Achor (2013). “Rethinking stress: the role of mindsets in determining the stress response.” J Pers Soc Psychol 104(4): 716-733.

Karatsoreos, I. N. and B. S. McEwen (2011). “Psychobiological allostasis: resistance, resilience and vulnerability.” Trends Cogn Sci 15(12): 576-584.

Kihlstrom, J. F. (2010). “Social neuroscience: The footprints of Phineas Gage.” Social Cognition 28: 757-782.

Kim, Y. and H. Chang (2011). “Correlation between attention deficit hyperactivity disorder and sugar consumption, quality of diet, and dietary behavior in school children.” Nutr Res Pract 5(3): 236-245.

Leaf, C. (2009). Who Switched Off My Brain? Controlling toxic thoughts and emotions. Southlake, TX, USA, Inprov, Ltd.

Nigg, J. T., K. Lewis, T. Edinger and M. Falk (2012). “Meta-analysis of attention-deficit/hyperactivity disorder or attention-deficit/hyperactivity disorder symptoms, restriction diet, and synthetic food color additives.” J Am Acad Child Adolesc Psychiatry 51(1): 86-97 e88.