Psychotic and manic-like symptoms during stimulant treatment of attention deficit hyperactivity disorder

A boy 6 years 9 months of age was brought by his mother to a child psychiatrist for difficulties with sustained attention, distraction, careless errors, poor listening, difficulty following instructions, difficulty with organization, frequently misplaced items, and forgetfulness in daily activities. He had no history of impulsive or hyperactive behavior, mood symptoms, or tics. He had been born after an unremarkable full- term pregnancy to a 43- year- old mother who did not use alcohol or drugs during pregnancy. The child was delivered by cesarean section after failure to progress in labor and had a normal postnatal course. His family history was negative for mood disorders, psychosis, obsessive- compulsive symptoms, or tics. Several months later, the symptoms had been confirmed in the home, school, and tutoring environments. The patient, then 7 years 4 months of age, was started on methylphenidate, and he showed a clear dose- response effect. An extended- release formulation of methylphenidate was then prescribed, and the dose was gradually increased over a 2- month period to 40 mg per day. At this dose, the patient had a strongly beneficial response, and the only side effect noted was mild anorexia. Eight months later, at 8 years 3 months of age, after a flu- like illness, he developed new symptoms, which included complaints of hearing voices and seeing " adults" when no one was present, a desire to " throw himself down the stairs," high levels of anxiety, tearfulness at school, an unwillingness to leave his mother's side, and irritability.