Abstract
Attention-deficit and hyperactivity disorder (ADHD) often presents with comorbid substance use disorder (SUD). The extant literature on the comorbidity of adult ADHD and SUD was summarized on the etiology, prevalence, diagnosis, and treatment. ADHD is diagnosed in 15–20% of SUD patients, mostly as ADHD with a combined presentation. ADHD and SUD are believed to have shared pathophysiology. ADHD is associated with the majority of dependence diagnoses. A most used screening questionnaire for screening ADHD patients presenting with SUD is the Adult ADHD Self-report Scale (ARSR). Evidence on pharmacological treatment is limited, but new trials support the use of long-acting stimulants as also recommended with a combination of psychotherapy by expert opinion. Given the prevalence of both ADHD and SUD, more research is needed to understand the theoretical and clinical implications of this comorbidity.