The effects of diazepam or diphenhydramine on healthy human subjects
The immediate effects on the mood and some mental and physical functions of a single oral dose of diazepam (10 mg) and diphenhydramine (50 mg) compared with placebo were studied in healthy human subjects. The material comprised 270 students divided into three similar groups. The mood was tested by the Nowlis adjective check list. The digit symbol test and number series were used to test the mental condition. The major significant results of the study were: diazepam decreased activity both in men and women and sociability in women. It increased euphoria in men and depressivity and withdrawing in women. It impaired the results in the digit symbol test and the ability to repeat the number series in both men and women. Diphenhydramine also decreased activity in men and women. It caused some euphoria in men. It had a slighter depressing effect than diazepam on the mental functions. The many different effects in women as compared with men did not seem to be caused only by larger dose per kg given to the former. This was confirmed by an additional study in which a smaller group of men was given the same dose/kg of the drugs as the women in the main study, and vice versa.