Psychotic Symptoms in Attention-Deficit/Hyperactivity Disorder: An Analysis of the MTA Database

To assess the prevalence of psychotic symptoms among youths (14-25 years of age) with a childhood diagnosis of attention-deficit/hyperactivity disorder (ADHD) combined type.

Participants in the Multimodal Treatment Study of Children with ADHD (MTA) and a local normative comparison group (LNCG) were systematically assessed 6, 8, 10, 12, 14, and 16 years after the original enrollment at a mean age of 8.5 years. Trained research assistants administered a psychosis screener, and positive screens were referred to study clinicians to confirm or exclude psychosis. Possible associations between screening positive and alcohol or substance use were assessed.

Data were available from 509 MTA participants (88% of original MTA sample; mean age 25.1 years) and 276 LNCG participants (96% of original sample; mean age 24.6 years) at year 16. Twenty-six MTA participants (5%; 95% CI 3-7) and 11 LNCG participants (4%; 95% CI 2-6) screened positive for at least 1 psychotic symptom (p = .60). Most psychotic symptoms were transient. The prevalence of clinician-confirmed psychotic symptoms was 1.1% (95% CI 0.2-2.1) in the MTA group and 0.7% (0-1.7) in the LNCG (p = .72). Greater cannabis use was reported by those who screened positive (p < .05) and were confirmed positive (p < .01).

There was no evidence that ADHD increased the risk for psychotic symptoms. In the ADHD and normative comparison groups, more frequent cannabis use was associated with a greater likelihood of experiencing psychotic symptoms, thus supporting the recommendation that youth should not use cannabis.