Researchers from the Department of Psychology at the University of Southampton in the UK undertook meta-analyses of the efficacy of various non-pharmaceutical interventions for the treatment of ADHD (attention deficit hyperactivity disorder) – dietary approaches (restricted elimination diets, artificial food color exclusions, and free fatty acid supplementation) as well as psychological interventions (cognitive training, neurofeedback, and behavioral interventions).

The authors searched electronic databases to identify published, randomized, controlled trials that involved individuals who were diagnosed with ADHD and included an ADHD outcome.

Fifty-four of the 2,904 nonduplicate screened records were included in the analyses. Two different analyses were performed. When the outcome measure was based on ADHD assessments by raters closest to the therapeutic setting, all dietary (standardized mean differences=0.21-0.48) and psychological (standardized mean differences=0.40-0.64) treatments produced statistically significant effects.
However, when the best, probably blinded assessment was used, effects remained significant for free fatty acid supplementation (standardized mean difference=0.16) and artificial food color exclusion (standardized mean difference=0.42) but were substantially reduced to non-significant levels for other treatments.

The investigators conclude that free fatty acid supplementation produced small but significant reductions in ADHD symptoms, even with probably blinded assessments, although the clinical significance of these effects remains to be determined.

Artificial food color exclusion produced larger effects, but often in individuals selected for food sensitivities. 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 treatments for core ADHD symptoms.

Sonuga-Barke EJ, Brandeis D, Cortese S, Daley D, Ferrin M, Holtmann M, Stevenson J, Danckaerts M, van der Oord S, Döpfner M, Dittmann RW, Simonoff E, Zuddas A, Banaschewski T, Buitelaar J, Coghill D, Hollis C, Konofal E, Lecendreux M, Wong IC, Sergeant J; European ADHD Guidelines Group. Nonpharmacological interventions for ADHD: systematic review and meta-analyses of randomized controlled trials of dietary and psychological treatments. American Journal of Psychiatry. 2013 Mar 1;170 (3): pages 275-89. [email protected]