Faculty Bibliography

INTRODUCTION: An increasing number of clinical and epidemiological studies suggest a possible association between attention-deficit/hyperactivity disorder (ADHD) and obesity/overweight. However, overall evidence is mixed. Given the public health relevance of ADHD and obesity/overweight, understanding whether and to what extent they are associated is paramount to plan intervention and prevention strategies. We describe the protocol of a systematic review and meta-analysis aimed at assessing the prevalence of obesity/overweight in individuals with ADHD versus those without ADHD. METHODS AND ANALYSIS: We will include studies of any design (except case reports or case series) comparing the prevalence of obesity and/or overweight in children or adults with and without ADHD (or hyperkinetic disorder). We will search an extensive number of databases including PubMed, Ovid databases, Web of Knowledge and Thomson-Reuters databases, ERIC and CINAHL. No restrictions of language will be applied. We will also contact experts in the field for possible unpublished or in press data. Primary and additional outcomes will be the prevalence of obesity and overweight, respectively. We will combine ORs using random-effects models in STATA V.12.0. The quality of the study will be assessed primarily using the Newcastle-Ottawa Scale. Subgroup meta-analyses will be conducted according to participants' age (children vs adults) and study setting (clinical vs general population). We will explore the feasibility of conducting meta-regression analyses to assess the moderating effect of age, gender, socioeconomic status, study setting, geographic location of the study (low-income, middle-income countries vs high-income countries), definition of obesity, method to assess ADHD, psychiatric comorbidities and medication status. ETHICS AND DISSEMINATION: No ethical issues are foreseen. The results will be published in a peer-reviewed journal and presented at national and international conferences of psychiatry, psychology, obesity and paediatrics. REGISTRATION: PROSPERO-National Institute of Health Research (NIHR) Prospective Register of Systematic Reviews (CRD42013006410).

The exact etiopathophysiology of attention-deficit/hyperactivity disorder (ADHD) remains elusive, likely because of its phenotypic heterogeneity. Given the involvement of iron in neurocognitive and behavioral functions, iron deficiency (ID) has been suggested as a possible etiopathophysiological factor in a subsample of individuals with ADHD. Most studies assessing ID in ADHD have focused on serum ferritin, a marker of peripheral iron status. Results from these studies are mixed, and the largest studies failed to find a significant association between ADHD and low serum ferritin levels. However, serum ferritin may be influenced by several conditions, including inflammatory status. Increasing evidence, especially from epidemiological studies, points to a significant association between ADHD and obesity. Interestingly, obesity is associated with a chronic inflammatory status, characterized by ID with normal-to-high serum ferritin levels. This article reviews the literature on iron status in ADHD and on the relationship between ADHD and obesity; discusses a possible link among ADHD, ID, and obesity; and proposes that comorbid obesity contributes to ID, via chronic inflammation, in a subsample of individuals with ADHD. Thus, the comorbidity between ADHD and obesity suggests moving beyond serum ferritin levels and assessing the molecular pathways of chronic inflammation that lead to ID in individuals with ADHD and obesity. In turns, this may pave the way for novel treatment strategies for cognitive and behavioral dysfunctions related to ID in ADHD.

OBJECTIVE: Behavioral interventions are recommended as attention-deficit/hyperactivity disorder (ADHD) treatments. However, a recent meta-analysis found no effects on core ADHD symptoms when raters were probably blind to treatment allocation. The present analysis is extended to a broader range of child and parent outcomes. METHOD: A systematic search in PubMed, Ovid, Web of Knowledge, ERIC, and CINAHAL databases (up to February 5, 2013) identified published randomized controlled trials measuring a range of patient and parent outcomes for children and adolescents diagnosed with ADHD (or who met validated cutoffs on rating scales). RESULTS: Thirty-two of 2,057 nonduplicate screened records were analyzed. For assessments made by individuals closest to the treatment setting (usually unblinded), there were significant improvements in parenting quality (standardized mean difference [SMD] for positive parenting 0.68; SMD for negative parenting 0.57), parenting self-concept (SMD 0.37), and child ADHD (SMD 0.35), conduct problems (SMD 0.26), social skills (SMD 0.47), and academic performance (SMD 0.28). With probably blinded assessments, significant effects persisted for parenting (SMD for positive parenting 0.63; SMD for negative parenting 0.43) and conduct problems (SMD 0.31). CONCLUSION: In contrast to the lack of blinded evidence of ADHD symptom decrease, behavioral interventions have positive effects on a range of other outcomes when used with patients with ADHD. There is blinded evidence that they improve parenting and decrease childhood conduct problems. These effects also may feed through into a more positive parenting self-concept but not improved parent mental well-being.

Increasing attention is being paid to the relationship between attention deficit/hyperactivity disorder (ADHD) and obesity. While most available research focused on determining the extent of the association between ADHD and obesity, a few studies have examined the clinical implications of diagnosing/treating ADHD in individuals with obesity. Here, we provide a narrative review of studies addressing the impact of ADHD, or its treatment, in individuals with obesity. Reviewed studies suggest that ADHD impedes the successful treatment of obesity in individuals with comorbid ADHD and obesity. Preliminary evidence also suggests that ADHD treatment might significantly increase the effectiveness of weight management strategies. We discuss the limitations of the reviewed studies and provide suggestions for future research in the field.

BACKGROUND: The efficacy of three dietary treatments for ADHD has been repeatedly tested in randomized controlled trials (RCTs). These interventions are restricted elimination diets (RED), artificial food colour elimination (AFCE) and supplementation with free fatty acids (SFFA). There have been three systematic reviews and associated meta-analyses of the RCTs for each of these treatments. SCOPE: The aim of this review is to critically appraise the studies on the dietary treatments of ADHD, to compare the various meta-analyses of their efficacy that have been published and to identify where the design of such RCTs could be improved and where further investigations are needed. FINDINGS: The meta-analyses differ in the inclusion and exclusion criteria applied to potentially eligible studies. The range of average effect sizes in standard deviation units is RED (0.29-1.2), AFCE (0.18-0.42) and SFFA (0.17-0.31). The methodology of many of the trials on which the meta-analyses are based is weak. CONCLUSIONS: Nevertheless, there is evidence from well-conducted studies for a small effect of SFFA. Restricted elimination diets may be beneficial, but large-scale studies are needed on unselected children, using blind assessment and including assessment of long-term outcome. Artificial food colour elimination is a potentially valuable treatment but its effect size remains uncertain, as does the type of child for whom it is likely to be efficacious. There are additional dietary supplements that have been used with children with ADHD. A systematic search identified 11 RCTs that investigated the effects of these food supplements. Despite positive results for some individual trials, more studies are required before conclusions can be reached on the value in reducing ADHD symptoms of any of these additional supplements.