By Timothy Wilens, M.D.,Psychiatric Times.
The overlap between attention-deficit/ hyperactivity disorder and alcohol or drug abuse or dependence (referred to here as substance use disorders [SUDs]) in adolescents has been an area of increasing clinical, research and public health interest. Appearing in early childhood, ADHD affects from 6% to 9% of children and adolescents worldwide (Anderson et al., 1987) and up to 5% of adults (Kessler, in press). Longitudinal data suggest that childhood ADHD persists into adolescence in 75% of cases and into adulthood in approximately one-half of cases (for review, see Weiss, 1992). Substance use disorders usually appear in adolescence or early adulthood and affect between 10% to 30% of U.S. adults and a less defined, but sizable, number of juveniles (Kessler, 2004). The study of comorbidity between SUDs and ADHD is relevant to both research and clinical practice in developmental pediatrics, psychology and psychiatry with implications for diagnosis, prognosis, treatment and health care delivery.
Overlap Between ADHD and SUD
Structured psychiatric diagnostic interviews assessing ADHD and other disorders in substance-abusing groups have indicated that from one-third to one-half of adolescents with SUDs have ADHD (DeMilio, 1989; Milin et al., 1991). For example, aggregate data from government-funded studies of mainly cannabis-abusing youth indicate that ADHD is the second most common comorbidity with from 40% to 50% of both girls and boys manifesting full criteria for ADHD. Data largely ascertained from adult groups with SUDs also show an earlier onset and more severe course of SUD associated with ADHD (Carroll and Rounsaville, 1993; Levin and Evans, 2001).
There is a strong literature supporting a relationship between ADHD and SUDs. Both family/genetic and self-medication influences may be operational in the development and continuation of SUDs in ADHD. Adolescents with ADHD and SUDs require multimodal interventions incorporating addiction and mental health treatment. Pharmacotherapy in individuals with ADHD and SUDs needs to take into consideration timing, misuse and diversion liability, potential drug interactions, and compliance concerns.
While the existing literature has provided important information on the relationship of ADHD and SUDs, it also points to a number of areas in need of further study. The mechanism by which untreated ADHD leads to SUDs, as well as the risk reduction of ADHD treatment on cigarette smoking and SUDs, needs to be better understood. Given the prevalence and major morbidity and impairment caused by SUDs and ADHD, prevention and treatment strategies for these adolescents need to be further developed and evaluated.
Source: Psychiatric Times January 2006 Vol. XXV Issue 1