ADHD, stimulant treatment in childhood and subsequent substance abuse in adulthood - a naturalistic long-term follow-up study.

The purpose of the study was to estimate the risk of substance use disorder (SUD) and alcohol abuse in adulthood among children and adolescents with attention-deficit hyperactivity disorder (ADHD) compared to the background population. Furthermore, to examine whether the age at initiation and duration of stimulant treatment in childhood predicts SUD and alcohol abuse in adulthood. 208 youths with ADHD (183 boys; 25 girls) were followed prospectively. Diagnoses of SUD and alcohol abuse were obtained from The Danish Psychiatric Central Register. The relative risk (RR) of SUD and alcohol abuse for cases with ADHD, compared to the background population was 7.7 (4.3-13.9) and 5.2 (2.9-9.4), respectively. Female gender, conduct disorder in childhood and older age at initiation of stimulant treatment increased the risk of later SUD and alcohol abuse. Our results warrant increased focus on the possibly increased risk of substance abuse in females with ADHD compared to males with ADHD.