Attention-Deficit/Hyperactivity Disorder (ADHD) is a common childhood behavioural disorder -- systematic reviews demonstrate that the community prevalence of ADHD worldwide is between 2% to 7%, with an average of around 5%. Additionally, a Additional 5 percent of kids have significant issues with over-activity, inattention and impulsivity that are only sub-threshold to meet full diagnostic criteria for ADHD. Estimates of the administrative (clinically accepted and/or documented ) prevalence vary worldwide and although rising over the years, ADHD remains relatively under-recognised and under-diagnosed in many countries, especially in women and older kids. The timely recognition and treatment of children with ADHD-type difficulties provides a chance to improve their long-term outcomes. This review includes a systematic review of the community and administrative prevalence of ADHD in children and adolescents; an overview of the obstacles to accessing care for ADHD; a description of prices connected with ADHD; along with a broad discussion of evidence- based pathways for the delivery of clinical care, such as a focus on key issues for just two specific age groups - preschool children and adolescents requiring transition of care from kid to adult services.
At least a further 5% of children have significant difficulties with these behaviors that are just sub-threshold to meet full diagnostic criteria. ADHD often persists into adulthood and is a risk factor for a wide array of other mental health issues including defiant, disruptive, and antisocial behaviors, emotional problems, self-harm and substance misuse as well as broader negative outcomes like educational under-achievement and exclusion from school, difficulties with employment and relationships, and criminality.2-4 For health, education and social care services, the timely and appropriate recognition and treatment of children with ADHD-type problems provides an opportunity to boost their long-term outcomes. This review comprises a systematic review of the administrative and community incidence of ADHD in children and adolescents; an overview of the barriers to accessing care; a description of costs related to ADHD; and a discussion of evidence-based pathways and the delivery of clinical care, with consideration of certain issues relating to two age groups (pre-school children and adolescents requiring transition into adult services). Although ADHD treatments are not discussed in detail, key approaches to intervention are summarized as they apply to care pathways.
Prevalence of ADHD
Community prevalence describes the amount of individuals with ADHD in a representative population sample, according to predefined criteria. A series of searches (see Panel) identified seven systematic review articles reporting on the community prevalence of ADHD. The first review (Polanczyk) estimated that the global prevalence of ADHD as 5.29%.5 According to DSM-IV criteria and using symptoms from parent ratings, teacher ratings or best estimate diagnostic processes, Willcutt estimated an incidence of 5.9%-7.1% amongst children and teens.6 In contrast, Erskine et al's meta-analysis embraced a more conservative approachby applying a higher weight to research where information was required from more than one informant and also contained a greater percentage of 12-18 years olds compared to Polanczyk review.7 They estimated that the worldwide prevalence of ADHD amongst 5-19 year olds since 2.2%, with a peak prevalence in age 9 years. Polanczyk et al. upgraded their previous review, including 154 studies using either DSM or ICD diagnostic criteria in people aged 18 or below, and concluded that the world-wide community prevalence of ADHD is approximately 5 percent.8 Variation in estimated prevalence was best explained by methodological differences between studies so that when similar methodologies are adopted there was no obvious variation between different geographical locations. Neither were there differences by study year, implying that the community prevalence of ADHD has remained steady over the past few decades. Using incidence data from their previous review (the Global Burden of Disease Study 2010),7 Erskine et al conducted an additional systematic review to gauge the disability adjusted life years (DALYs) related to ADHD. ADHD was reported to contribute 491,500 DALYs,which makes it the 98th highest cause for global burden. As part of a wider meta-analysis of the worldwide prevalence of psychological disorders in children and adolescents, Polanczyk et al. estimated the incidence of ADHD in 6-18 year olds as 3.4% (95% CI 2.6 to 4.5) with heterogeneity in methods between research cited as a reason for different incidence estimates.10 The final inspection, by Thomas et al., included studies in any language which used DSM-III, DSM-III-R or DSM-IV criteria.11
