ADHD Studies Shed Little Light on Efficacy of Nonpharma Tx

Caroline Cassels

January 30, 2013

Poor scientific assessment of nonpharmacologic treatments — including dietary and psychological therapies — for attention-deficit/hyperactivity disorder (ADHD) is leaving physicians and their patients in the dark about their efficacy, new research suggests.

Conducted by the European ADHD Guidelines Group, a multidisciplinary and multinational group of ADHD experts, the meta-analysis showed that the positive effects on ADHD symptoms reported with cognitive training, neurofeedback, behavioral interventions, and exclusion of foods associated with hypersensitivity were lost when the analyses were restricted to blinded studies.

"Having reliable evidence about existing treatments is the first step in developing better ones. By comparing blinded and unblinded ratings, our analyses have provided new insights into ADHD treatments, the full clinical implications of which now need to be worked through carefully," lead author Edmund J. S. Sonuga-Barke, PhD, professor in psychology and developmental psychopathology and director, Developmental Brain-Behaviour Laboratory, University of Southampton, United Kingdom, said in a statement.

"Clinicians and basic scientists need to work together to find ways to implement current treatments more effectively and to use our understanding of ADHD pathophysiology to find more effective nonpharmacological interventions," he added.

The study was published online January 30 in the American Journal of Psychiatry.

Inflated Effect Sizes?

A common disorder that affects individuals across their lifespan, ADHD is associated with a variety of poor outcomes, including academic failure, interpersonal problems, mental illness, and delinquency. Furthermore, it carries significant societal costs, including a significant burden on families as well as healthcare and criminal justice systems.

According to the investigators, multimodal approaches are recommended for the treatment of ADHD. They note that although pharmacologic treatments are effective and widely used, they have significant limitations, including the following:

  • Normalization is rare;

  • Long-term efficacy has not been established;

  • They have adverse effects on sleep, appetite, and growth;

  • Parents and clinicians have concerns about medication use.

The authors point out that although a variety of nonpharmacologic approaches are available for ADHD, it is not clear from the literature whether they have a positive impact on core symptoms of the disorder.

The investigators note that, in part, this is because the research includes nonrandomized trials, non-ADHD outcome measures, or non-ADHD samples. Furthermore, the authors note, "estimates of efficacy are often based on assessment made by individuals who are likely to be aware of study allocation, which may inflate effect sizes."

To address these limitations, the investigators conducted a meta-analysis that included both dietary and psychological domains of ADHD treatments.

"Our goal was to survey the field to prepare evidence-based clinical guidelines for the nonpharmacological treatment of ADHD," they write.

The researchers identified 54 published, randomized controlled trials that involved individuals diagnosed with ADHD and that included an ADHD outcome and met the inclusion criteria for the meta-analysis.

The primary outcome was pre- to post-treatment change in total ADHD symptom severity measured at the first post-treatment assessment.

The analysis included 7 studies that examined restricted elimination diets, 8 trials of artificial food color exclusions, 11 studies of free fatty acid supplementation, 6 trials of cognitive training, 8 neurofeedback studies, and 15 behavioral intervention trials.

Better Research

The investigators found positive effects on ADHD symptoms for all interventions when raters were unblinded. However, under blinded conditions, statistically significant effects on ADHD symptoms were only found for omega-3/omega-6 fatty acids or elimination of artificial food colorings, although these effects were small and/or restricted to food-sensitive individuals.

Many of the studies included in the analysis also incorporated medications. When investigators only included studies in which medication was not used in either the treatment or control arm, the advantage of the artificial food color restriction was reduced. However, the small effect of free fatty acids remained.

The researchers conclude that "better evidence for efficacy from blinded assessments is required for behavioral interventions, neurofeedback, cognitive training, and restricted elimination diets before they can be supported as treatment for core ADHD symptoms."

"The challenge for the future is to improve the efficacy of nonpharmacological interventions...with pharmacological approaches. Properly powered, randomized controlled trials with blinded, ecologically valid outcome measures are urgently needed, especially in the psychological treatment domain. Future trials should focus across a broader range of child-, parent-, family-related functional outcomes," the authors write.

Dr. Sonuga-Barke reports that he has been involved in the development, implementation, and trialing of the New Forest Parenting Programme for preschool children with ADHD and has received royalties from sales of a New Forest Parent Training self-help manual; he has served as a speaker, adviser, or consultant for AstraZeneca, Flynn Pharma, Shire, and UCB Pharma; he has received conference support from Shire; and he has received research support from Janssen-Cilag, Shire, and Qbtech. The disclosures of the other authors can be found in the original study.

Am J Psychiatry. Published online January 30, 2013. Abstract