Résumé
Attention deficit hyperactivity disorder (ADHD) is a childhood-onset neurodevelopmental disorder which may persist into adulthood with a worldwide prevalence of 2,5%. First diagnosis and treatment in adults is a growing trend, methylphenidate (MPH) being one of the most prevalent choices of medication. MPH may be associated with psychotic events according to safety studies in children. This review aims to explore the risk of incident psychotic symptoms and disorders after MPH introduction in adults.We conducted a systematic review of studies of all designs which examine MPH initiation in ADHD adults as intervention and incident risk of psychotic events as outcome. We ran a narrative review and quality assessment of the sample. No meta-analysis was run owing to the scarcity of data.Our systematic search yielded 6 articles, of which 2 nation-wide registry-based observational studies and 4 case-reports/series. The narrative review does not suggest a higher risk of psychotic events secondary to MPH initiation and highlights a possible higher baseline risk in ADHD patients and more so if there is a comorbid SUD.These conclusions are hindered by the lack of good quality studies. Future research should aim to produce RCTs designed to elicit such rare events and should consider the growing interest in MPH to treat negative symptoms of schizophrenic disorder, as well as the body evidence suggesting a direct link between ADHD and psychotic disorders.