An 8-year-old boy with a transient but severely debilitating obsessive-compulsive disorder (OCD), induced by a brief course of methylphenidate (MPH) (10 mg/daily) for treatment of mild, uncomplicated attention deficit hyperactivity disorder, is reported from the University of Illinois College of Medicine, Rockford, Illinois. After 2 weeks of MPH treatment, school work improved, but OC behaviors emerged: avoidance of touching objects, repeated hand washing. He also developed tics involving head and neck. The past history was negative for psychiatric comorbidity, recent streptococcal infection, and familial anxiety disorders. Withdrawal of MPH was followed by gradual recovery from the OCD over a 3 month period. 
COMMENT. Obsessive compulsive disorder (OCD) is a rarely reported complication of psychostimulant therapy for ADHD. The author cites only two previous references. Dextroamphetamine has been implicated more often than methylphenidate (MPH). Tic disorder is a comorbid complication and a more frequent side effect of MPH than OCD. The above report should prompt a greater awareness of the potential risk of OCD in addition to tics in ADHD children treated with MPH. As with MPH-induced seizures, the incidence of this side effect may be higher than the literature documents.
Psychiatric, neuropsychological, and psychosocial features of DSM-IV subtypes of ADHD were assessed in 413 children and adolescents referred to the Pediatric Psychopharmacology Unit, Massachusetts General Hospital, Boston, MA. Combined-type subjects showed the greatest psychiatric impairments compared to other subtypes, but no differences in cognitive or psychosocial functioning. Inattentive subjects were more likely to require extra help in school. Hyperactive-impulsive patients were not different from controls on measures of depression, social functioning, IQ, and academic achievement.