Attention deficit hyperactivity disorder (ADHD) among illicit psychostimulant users: a hidden disorder?

Aims To estimate the prevalence, nature and correlates of symptomatology consistent with adult attention deficit hyperactivity disorder (ADHD) among illicit psychostimulant users. Design Cross-section survey. Setting Sydney, Australia. Participants 269 regular illicit psychostimulant users. Measurements Structured interview assessing demographics, drug use and treatment history, psychostimulant dependence and self-reported symptoms consistent with adult ADHD. Findings Almost half (45%) screened positive for adult ADHD (ADHD+). Symptoms of inattention (90%) were more prevalent than symptoms of hyperactivity/impulsivity (57%). Of those who screened positive for adult ADHD, only 17% had received a prior diagnosis of ADHD. The ADHD+ group differed from other participants in several respects: an earlier initiation of substance use and injecting drug use; more extensive polydrug use; a higher frequency of recent stimulant use and injecting drug use; a greater likelihood of stimulant dependence; and a greater likelihood of having received treatment for drug dependence. After controlling for other factors, screening positive for ADHD was associated independently with fewer years of education, earlier initiation of regular tobacco use and more extensive life-time polydrug use. Conclusions Clinicians should be aware of the potential for patients of drug and alcohol treatment services to have undiagnosed and/or untreated ADHD that may impact on their compliance with, and retention in, treatment.