Open letter to Professor Michael Kohn
Dear Professor Michael Kohn,
Despite significant longstanding evidence to the contrary a recent article in the Daily Telegraph stated:
“Westmead Hospital pediatrician Professor Michael Kohn, who has patients under the age of six, said… more evidence had recently come to light which confirmed that children with ADHD had brains that developed slower. Stimulant medication like Ritalin helped brain growth. “Children with ADHD have a lower rate of brain growth and development and they do not reach the same peak of brain growth that children without ADHD do,” Prof Kohn said. “When we give them stimulant medication, scans show a more normal pattern of brain development than would otherwise have occurred.“
This letter seeks evidence supporting your claim that giving ‘ADHD’ children stimulants, amphetamines (dexamphetamine) and amphetamine-like drugs (Ritalin, Concerta) aids in ‘brain development’. I am very surprised by this claim as numerous studies have long established that the use of psycho-stimulants by children has regularly resulted in gross malfunctions in the brain, and ‘can cause shrinkage (atrophy) or other permanent physical abnormalities.’ As this is the opposite of what you are claiming, I would like to have access to any contradictory new evidence and if it is valid help to publicise it. If, however, there is not adequate supporting evidence I would welcome an explanation of why you made this surprising claim.
I would also like to have access to the evidence supporting your claim that ‘children with ADHD have a lower rate of brain growth and development and they do not reach the same peak of brain growth that children without ADHD do’. I am aware of previous similar discredited claims in studies which purported to show differences in brain growth in ADHD and non-ADHD brains. Amongst numerous methodological flaws these studies compared ‘non ADHD brains’ that have never been medicated, to ‘ADHD brains’ that have been atrophied by previous exposure to psycho-stimulants. In the past this important point has not been highlighted in arguments used to justify giving children ADHD amphetamines. If you have new valid evidence I would appreciate access to it. If not, I wonder what efforts you are going to make to correct the record with Daily Telegraph readers.
Some readers of the Daily Telegraph article may also have been left with the impression that you prescribe Ritalin to children 5 and younger. Obviously I presume you never prescribe any methylphenidate product (including Ritalin) to your patients ‘under the age of six’ as you are undoubtedly aware methylphenidate is NOT APPROVED for use in children under 6 years of age. This is because methylphenidates’ safety and efficacy in this age group has not been established. It might also be helpful to clarify this with Daily Telegraph readers.
I would welcome your early reply and offer you the opportunity to post it unedited on my website.
Martin Whitely MLA
21 June 2011
Update: 3 October 2012 Still no answer from Professor Kohn
 Peter R. Breggin, M.D., Talking Back to Ritalin: What Doctors Aren’t Telling You about Stimulants for Children, Common Courage Press, Monroe, 1998, p. 358. Jonathan Leo & David Cohen, ‘Broken Brains or Flawed Studies? A Critical Review of ADHD Neuroimaging Research’, the Journal of Mind and Behaviour, Winter 2003, Vol 24, 1: p29 http://psychrights.org/research/Digest/NLPs/criticalreviewofadhd.pdfaccessed 21 June 2011 Medication Guide: Ritalin-SR. Available at http://www.dailytelegraph.com.au/news/rising-rate-of-adhd-drugs-for-kids-like-ritalin/story-e6freuy9-1226073934249