Porfirio 2011.

Methods	A patient report of visual hallucinations during methylphenidate treatment
Participants	Diagnosis of ADHD: DSM‐IV (subtype: combined) Age: 7 years at diagnosis, 11 years at occurrence of hallucinations IQ: above 70 Sex: male Ethnicity: not stated Country: Italy Comorbidity: K‐SADS‐PL excluded any psychiatric comorbidities (at age 11) Comedication: not stated Sociodemographics: mother presented with affective seasonal disorder and binge eating disorder
Interventions	Methylphenidate type: oral immediate‐release Methylphenidate dosage: 0.5 mg/kg twice daily (30 mg/day) Duration of treatment: 3 years with discontinuation of medication during summer time each year Treatment compliance: not stated
Outcomes	Serious adverse events: 3 years after start of MPH treatment: an episode of complex visual hallucinations (dramatic scenes appearing before going to sleep, sometimes during the day after methylphenidate‐ingestion). Normal physical and neurological examinations. Standard laboratory work‐up and drug screening were within normal limits. Normal visual acuity. Sleep electroencephalography (EEG) revealed no abnormalities and no evidence of epileptic activity. K‐SADSPL excluded any psychiatric comorbidities Discontinuation: complete resolution of hallucinations 24 months follow‐up period: no further hallucinations occurred
Notes	Key conclusions of the study authors: 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 Comments from the study authors: because methylphenidate is a widely used, well studied and safe pharmacological agent, clinicians who prescribe methylphenidate should be aware of this possible rare adverse manifestation occurring at therapeutic doses Funding/vested interest/authors' affiliations: not stated Supplemental information regarding IQ received through personal email correspondence with the authors in October 2013 (Curatolo 2013 [pers comm])