INTRODUCTION: Prevalence estimates of attention deficit hyperactivity disorder (ADHD) vary according to the diagnostic criteria used and the population sampled. DSM-5 prevalence estimate among school children in the US is 5%, but other estimates vary from 2% to 16%. No objective test exists to confirm the diagnosis of ADHD, which remains a clinical diagnosis. Other conditions frequently co-exist with ADHD. METHODS AND OUTCOMES: We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of nutritional supplements in children and adolescents with ADHD? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2014 (BMJ Clinical Evidence overviews are updated periodically, please check our website for the most upto-date version of this overview). RESULTS: At this update, searching of electronic databases retrieved 157 studies. After deduplication and removal of conference abstracts, 91 records were screened for inclusion in the review. Appraisal of titles and abstracts led to the exclusion of 29 studies and the further review of 62 full publications. Of the 62 full articles evaluated, four additional systematic reviews were included at this update. We performed a GRADE evaluation for two PICO combinations. CONCLUSIONS: In this systematic overview, we categorised the efficacy for three interventions, based on information relating to the effectiveness and safety of iron supplements, omega-3 polyunsaturated fatty acids, and zinc supplements.
QUESTIONSWhat are the effects of nutritional supplements in children and adolescents with attention deficit hyperactivity disorder (
Key points• Core symptoms of attention deficit hyperactivity disorder (ADHD) are inattention, hyperactivity, and impulsiveness, although other conditions frequently co-exist with ADHD, including developmental disorders (especially motor, language, autism spectrum disorder, and specific learning disabilities) and psychiatric disorders (especially oppositional defiant and conduct disorder, anxiety, and depressive disorders).DSM-5 criteria state that symptoms must be present for at least 6 months, are generally observed in children before the age of 12 years, and cause clinically important impairment in social, academic, or occupational functioning that must be evident in more than one setting.Formal diagnostic criteria are most applicable to boys aged 6 to 12 years, and most research data relate to this group. Pre-school children, adolescents, adults, and females may present less typical features, but similar levels of impairment.The global prevalence estimates of ADHD are 5.3% for children and adolescents and 4.4% in adulthood, although there is significant variability in the prevalence estimates worldwide, largely explained by methodological procedures.• We searched for evidence from RCTs and systematic reviews of RCTs on the effectiveness of nutritional supplements (omega-3, iron, or zinc) in children and adolescents with ADHD.We found few RCTs that met our i...