Folate levels in psychiatric outpatients.

This study examines folate in psychiatric outpatients. Fifty-three outpatients with schizophrenia and 24 outpatients with depressive disorder assessed with the Schedules for Clinical Assessment in Neuropsychiatry interview are included. Patients with schizophrenia had lower serum folate levels than age- and sex-matched controls, while red cell folate levels did not differ. Serum folate levels showed a negative correlation with the Clinical Global Impression, disorganized dimension, and total Positive and Negative Syndrome Scale score. Patients with depressive disorder had lower serum folate levels than healthy controls, but showed no differences in red cell folate levels. Only two patients with schizophrenia had red cell folate levels below the normal range.