The primary purpose of this study was to determine the effect upon behavior of withdrawing chlorpromazine treatment after it had been established as the preferred treatment routine.Four groups of patients, each containing 28 chronic schizophrenics matched for length of treatment on clinical dosage of chlorpromazine, were studied intensively for 6 months. During the first 3 months, groups PP and PT were given placebo tablets while groups TP and TT were continued on chlorpromazine. Groups PP and TP were given placebo during the second 3-month period, while the other two groups received chlorpromazine. Behavior ratings by nursing personnel were gathered on each of the 112 patients every 3 weeks, using the MSRPP. Independent ratings were made by the ward psychiatrist every 3 months. Measures of mental functioning were also obtained at the beginning, middle, and end of the experiment by a psychologist using the Army Beta, the Bender-Gestalt, and the Draw-A-Person tests.Abstract Teaser