Packages of Care for Attention-Deficit Hyperactivity Disorder in Low- and Middle-Income Countries

Attention-deficit hyperactivity disorder (AD/HD) is a chronic, pervasive developmental disorder that, although usually diagnosed in childhood, spans the preschool to adult years. The most recent version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) defines the disorder using the core features of age-inappropriate hyperactivity, impulsivity, and inattention (Box 1) [1]. The 10th edition of the International Classification of Diseases (ICD-10) provides operational criteria for the similar, but more severe and narrowly defined hyperkinetic disorder (HKD) [2]. We have used the term AD/HD throughout this paper because most of the published literature relates to the broader concept of AD/HD rather than to HKD. A rapidly expanding body of literature from lowand middleincome countries (LMICs) largely refutes the notion that AD/HD is a ‘‘Western’’ concept, although cultural factors clearly influence illness perceptions and help-seeking behavior [3–7]. A systematic review and meta-regression analysis of 102 studies from all continents concluded that the worldwide pooled prevalence of AD/HD is 5.3%, and that the geographic variability between AD/HD prevalence estimates is best explained by the methodological characteristics of the studies [8]. A strong body of evidence from high-income countries (HICs) suggests that AD/HD is a neurobiological syndrome with complex genetic factors primarily implicated in its etiology. Although individual risk alleles identified by molecular genetic studies increase the risk of AD/HD only slightly, the mean estimate of total heritability is just under 80% [9]. A wide range of social determinants significantly influence the symptomotology of AD/ HD in HICs. These include low socioeconomic status, low parental education, family conflict, parental mental disorder, severe early deprivation, and institutional upbringing [9–11]. The involvement of these multiple determinants in the symptomatology of AD/HD is consistent with the hypothesis that AD/HD is an etiologically heterogeneous, final common pathway disorder that is influenced by genes, environment, and gene–environment interactions. Other nongenetic causes of AD/HD identified in HICs are factors that affect early brain development, such as perinatal stress, low birth weight, prenatal smoking and alcohol use, obstetric complications, head injury, epilepsy, and HIV/AIDS [9–11]. The mediating and moderating influence of these variables on the development of AD/HD amongst children in LMICs is less well researched and does not always match with that seen in HICs [11]. The Evidence on the Treatment of AD/HD