Abstract
George Halasz, Honorary Senior Lecturer, Department of Psychological Medicine, Monash Medical Centre, Clayton, Victoria, Australia:
Two emerging lines of ‘evidence’ are currently creating a conundrum in child psychiatry. On the one hand, increasing evidence emerging from brain studies with magnetic resonance imaging (MRI) in attention deficit hyperactivity disorder (ADHD) have opened new frontiers in child psychiatry. Rapoport et al. [1] review seven studies pointing to brain differences in males and females with ADHD suggesting an ‘early non-progressive “lesion” involving neurotrophic factors controlling overall brain growth and selected dopamine circuits’ (p.272). They argue a ‘strongly genetic nature of ADHD’ (p.277) with the implication that the anatomical differences in ADHD ‘probably occur early in neurodevelopment… in utero (second or third trimester) can affect the brain development and size globally, thus explaining the changes seen in ADHD’.
On the other, we witnessed in the last decade increasing public and professional concerns centred on the diagnosis and the psychopharmacological treatment of ADHD in very young children [2]. Research studies on ADHD are based on the assumption that the condition has been ‘proven’ to exist. In the current evidence-based medicine culture, I draw attention to Jensen's [3] National Institute of Health (NIH) ADHD consensus statement on the scientific evidence to support ADHD as a disorder.
Based on 31 scientific ‘testimonies’ to a scientific ‘jury’, the NIH Consensus Statement concluded: ‘tentative support for, but nonetheless “unproven” status of the disorder should give pause to both researchers and clinicians who may have reified ADHD as a “thing” or a “true entity” (rather than a working hypothesis (italics) that serves scientific, communication, and clinical decisionmaking purposes).’
Against this background, a case could be made for current ADHD research published without reference to the ‘unproven’ status of ADHD to be judged by peer reviewers as ignoring critical scientific ‘evidence’.