Childhood-onset schizophrenia: brain MRI rescan after 2 years of clozapine maintenance treatment.

The effect of clozapine on striatal morphology was examined in adolescents with childhood-onset schizophrenia. Eight adolescent patients with onset of psychosis before age 12 and eight matched comparison subjects had initial and 2-year follow-up brain magnetic resonance imaging scans. Basal ganglia and lateral ventricle volumes were measured. The patients were on a clozapine regimen during the 2-year interim. Caudate volume was larger in the patients at the initial scanning, decreased in the patients between scans, and did not differ significantly between the patients and the comparison subjects at the second scanning. Caudate enlargement in patients with childhood-onset schizophrenia who are taking typical neuroleptics appears to be secondary to medication exposure. Rescanning to examine basal ganglia morphology is indicated for these patients when they are taking an atypical neuroleptic.