Use of services and associated costs for young adults with childhood hyperactivity/conduct problems: 20-year follow-up

Kapil Sayal, Division of Psychiatry & Applied Psychology, University of Nottingham, E Floor, South Block, Queen's Medical Centre, Nottingham NG7 2UH, UK. Email: [email protected]

Declaration of interest

None.

There is increasing evidence that problems related to childhood attention-deficit hyperactivity disorder (ADHD) can persist into early adulthood and that they can act as a risk factor for the development of additional problems including other psychiatric disorders, substance misuse, educational underachievement, difficulties with employment and relationships, and criminality. ^1-5 Findings from the USA highlight that children who have received a clinical diagnosis of ADHD use more services and incur greater costs than children without ADHD. ^6-8 Although a clearer picture is emerging in the UK about the recognition of and use of services by children and adolescents with hyperactivity and inattention problems, ^9,10 little is known about their use of services and associated costs once they enter adulthood and take on greater responsibility for initiating help-seeking.

A recent review of the US literature on the cost of illness related to ADHD has highlighted that its economic impact is about three times greater in relation to affected adults than children and adolescents. ¹¹ Most follow-up studies of ADHD into adulthood have relied on clinically referred samples. ^1-3 This means that children in these studies have been selected on the basis of their receipt of clinical services. Although a few studies have reported on later service use, ^3,12 their findings do not necessarily generalise to all children with ADHD, particularly in countries such as the UK, where the majority of affected children have not received specialist health services or a clinical diagnosis. ¹³ These studies have also tended to focus on the receipt of mental health services rather than the wider range of healthcare, social and criminal justice services to which people with ADHD might present. A further limitation of previous work relates to the role of comorbidity. Although childhood ADHD is frequently comorbid with conduct problems, studies have not investigated the relative contributions of ADHD and conduct problems in influencing later service use and costs.

In a prospective longitudinal study spanning 20 years (from 1981-1983 to 2002-2004), we aim to describe the use of services by and calculate recent (past 6 months) and early adulthood (since the age...