An evaluation of the double-blind trial as a method of assessing promazine (“Sparine”) in the treatment of chronic psychotic patients

Due to skin sensitivity of the nursing staff to chlorpromazine, a single ward contained female chronic schizophrenics who had not been treated with phenothiazines. A pilot trial on six patients showed marked improvement with a liquid preparation of Sparine (promazine hydrochloride) without affecting the allergic state of the nursing staff, so a double-blind trial in a further 50 patients was started. This consisted of three months therapy with Sparine and three months with placebo. Assessments were made daily and at the end of the study. Fifty-six per cent. of the patients made a clear-cut clinical improvement on Sparine, but this impression was not sustained by the analysis of the results of the double-blind trial. The possible reasons for this contradictory state of affairs are discussed.