Attention-deficit/hyperactivity disorder (ADHD) is frequently associated with other psychiatric conditions, including psychotic disorders. There is evidence for shared genetic susceptibility to both conditions,1 and first-degree relatives of people with ADHD have twice the risk of having schizophrenia compared with healthy controls.2
There is also an added risk of psychosis in patients with comorbid cannabis use. There are overlapping environmental risk factors for both disorders,…