Double blind trial of L-dopa in chronic schizophrenia

A double blind study in 28 patients with chronic schizophrenia was carried out comparing L-dopa (up to 1250 mgm daily) with placebo (both groups continuing to receive regular neuroleptic medication) over a six week period. Assessments by the psychiatrists and psychologist using Rockland and Pollin Rating Scale showed differential improvement of insignificant proportions but the nurse's ratings showed clearly significant improvement in the subject group.