Methylphenidate-induced visual hallucinations.

An 11-year-old boy with attention deficit/hyperactivity disorder (ADHD) presented with visual hallucinations several years after starting methylphenidate (MPH). The hallucinations resolved upon discontinuation of the drug. Reports of toxic hallucinosis during treatment with MPH are rare. Although the pathogenetic mechanism is unclear, the occurrence of hallucinations may be explained by a chronic increase in synaptic dopamine. Clinicians should be aware of this possible rare adverse manifestation occurring at therapeutic doses. © Georg Thieme Verlag KG Stuttgart · New York.