Monthly Archives: April 2014

The Reality of ADHD – CANDAL Researchers

In March 2014 the national media ran stories on the subject of ADHD based on interviews with a US academic. This article outlines the response from the Institute of Mental Health’s CANDAL centre of excellence.

The Observer (30.03.14) headlined an article: Children’s hyperactivity ‘is not a real disease’, says US expert. It reported an interview with Dr Bruce D Perry, Senior Fellow of the Child Trauma Academy in Houston, Texas.

Dr Perry is visiting Britain to meet cabinet members Ian Duncan Smith and Jeremy Hunt, as well as addressing the influential Early Intervention Foundation, chaired by Labour MP Graham Allen. Dr Perry is, to his credit, a prominent advocate of the idea that the way we treat children has profound effects on the way their brains develop physically, and that this has far-reaching consequences for their lifetime mental health. We entirely agree.

However, there are many things about the Observer’s report of its interview with Dr Perry that we find worrying, particularly the Observer’s rhetorical headline, and the potential impact of Dr Perry’s reported views on public understanding of and policy towards ADHD.

Dr Perry rightly says that ADHD describes a broad set of symptoms, and that many of us “at any given time” would fit “at least a couple” of the symptoms of ADHD. But this entirely misses the point that for a clinical diagnosis of ADHD, symptoms of inattention, hyperactivity and impulsivity must be severe, persistent and impairing. These difficulties present challenges that are all too real, and the role played by childhood trauma does not make them less so.

The NICE ADHD Guideline carefully reviewed evidence from numerous clinical trials and concluded that while behavioural interventions should be offered first to milder cases, pharmacological intervention is the most effective treatment for severe ADHD. As the Observer rightly notes, prescription rates for ADHD drugs in the UK have risen sharply in recent years. However, far from the rise being a scandal, it reflects a welcome trend towards greater access to care for children with ADHD, and prescription rates in the UK (in contrast to many parts of the US) remain well below the estimated prevalence of the condition.

Nonetheless there is legitimate cause for concern over long-term use of any drug during childhood. Dr Perry raises two concerns.

Firstly, he is reported as claiming that the evidence suggests there are no long term benefits of psychostimulants. Dr Perry may be referring to the rigorous Multi-modal Treatment study of ADHD (MTA)1,2. While results after 14 months of randomly allocated treatment showed clearly that carefully crafted medication treatment was more effective than state-of-the-art psychosocial treatment alone, or routine community care. However, naturalistic follow-up of the MTA sample after random treatment allocation ended at 14 months found that differences between the treatment groups diminished over timeand that serious functional impairments often remained3,4. Importantly, the results showed that treatment benefits were only maintained while carefully crafted medication was maintained. The implication is not that medication doesn’t work in the long term, but rather that effective treatment needs to be maintained for benefits to persist. This is similar to the management of other long term conditions such as hypertension and diabetes – where benefits are only persist if the treatment is given.

Secondly, Dr Perry reportedly argues that psychostimulants raise reward thresholds. But substantial evidence 5–8 indicates that raised reward thresholds are typical of untreated ADHD , a dysfunction attributable to an underlying deficit in the dopamine system, and that methylphenidate, which increases the amount of dopamine at brain synapses, actually lowers those thresholds, helping children to engage and concentrate better on less immediately rewarding activities such as school work, and be less distracted by the immediate stimulus or buzz provided bycomputer games, mobile phones and social media. 

Dr Perry states that we should be cautious about medication “particularly when the research shows you that other interventions are equally effective and over time more effective and have none of the adverse effects. For me it’s a no-brainer.”  Of course if this were true he’d be right, as no one should medicate children if other interventions that are safer and just as affective are available.  But research does not show that other (behavioural) interventions are “equally effective” for ADHD – indeed a recent study9 showed that even what evidence there was for the effectiveness of non-pharmacological interventions for ADHD largely disappeared when the children’s behaviour was rated by observers who did not know whether the child had received the intervention. Although politically unpalatable, it appears that the evidence for the effectiveness of existing behavioural interventions for ADHD has been oversold.

At CANDAL we are committed to developing and evaluating novel cognitive and behavioural therapies of exactly the kind that Dr Perry advocates, aimed at breaking the negative cycle of dysregulation, but clearly much more work needs to be done to make them effective.

We entirely agree with Graham Allen that “if you can diminish adverse childhood experience, then we eliminate a lot of the causes of dysfunction.”  We applaud Graham Allen’s efforts to focus public attention and government resources on “evidence-based programmes” that will help improve children’s mental health and reduce the “costly and damaging social problems”that can result from conditions such as ADHD.

Children with ADHD and their families in the U.K. deserve betterpublic understanding of the complex, multifactorial nature of this disabling condition and access to better treatments, not sensationalist and stigmatising headlines that suggest that these children and young people do not have a “real” condition.



Professor David Daley (

Professor Cris Glazebrook (

Professor Chris Hollis (

Professor Georgina Jackson (

Dr Elizabeth Liddle (

Professor Peter Liddle (

Professor Kapil Sayal (


Members of CANDAL Centre for ADHD and Neurodevelopmental Disorders Across the Lifetime, Institute of Mental Health, University of Nottingham.



  1. The MTA Cooperative Group. A 14-month randomized clinical trial of treatment strategies for attention-deficit/hyperactivity disorder. Arch. Gen. Psychiatry56, 1073–1086 (1999).
  2. Conners, C. K. et al. Multimodal treatment of ADHD in the MTA: An alternative outcome analysis. J. Am. Acad. Child Adolesc. Psychiatry40, 159–167 (2001).
  3. Molina, B. S. G. et al. The MTA at 8 Years: Prospective Follow-up of Children Treated for Combined-Type ADHD in a Multisite Study. J. Am. Acad. Child Adolesc. Psychiatry48, 484–500 (2009).
  4. MTA Cooperative Group. National Institute of Mental Health Multimodal Treatment Study of ADHD Follow-up: 24-Month Outcomes of Treatment Strategies for Attention-Deficit/Hyperactivity Disorder. Pediatrics113, 754–761 (2004).
  5. Rubia, K. et al. Methylphenidate normalises activation and functional connectivity deficits in attention and motivation networks in medication-naive children with ADHD during a rewarded continuous performance task. Neuropharmacology57, 640–52 (2009).
  6. Johansen, E. B. et al. Origins of altered reinforcement effects in ADHD. Behav. Brain Funct.5, (2009).
  7. Liddle, E. B. et al. Task-related default mode network modulation and inhibitory control in ADHD: effects of motivation and methylphenidate. J. Child Psychol. Psychiatry52, 761–771 (2011).
  8. Groom, M. J. et al. Effects of Motivation and Medication on Electrophysiological Markers of Response Inhibition in Children with Attention-Deficit/Hyperactivity Disorder. Biol. Psychiatry67, 624–631 (2010).
  9. Sonuga-Barke, E. J. S. et al. Nonpharmacological Interventions for ADHD: Systematic Review and Meta-Analyses of Randomized Controlled Trials of Dietary and Psychological Treatments. Am. J. Psychiatry170, 275–289 (2013).

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