Thesis (Ph.D.)--Boston University / Since chlorpromazine was first developed it has found widespread use in the treatment of various mental dis orders, particularly schizophrenia. Research to date has suggested that the drug has an adverse effect on some psychological functions and a beneficial effect on others, particularly in the area of clinical symptoms. While some studies have led to the conclusion that the drug reduces the symptoms of psychiatric patients, other studies often do not support that conclusion. In the stuiies where psychiatric patients have been used as subjects for laboratory tasks, it has usually been assumed that the patient's psychiatric state has a detrimental effect on the performance of the task and it has been hypot he sized that chlorpromazine will increase task efficiency. The purpose of this study was to test the effect of chlorpromazine hydrochloride on stress-induced anxiety. There has been little effort to manipulate experimentally the emotional state of the subject and then to test the drug's ability to reduce the emotional state. One study, using normal human subjects, found that the drug did not reduce the detrimental effects of psychological stress. Two animal studies, however, indicated that the drug hastened the extinction of conditioned fear responses. [TRUNCATED]