Effects of morphine, chlorpromazine and chlordiazepoxide on shock-induced changes in basal skin conductance.

Chlorpromazine (12.5 and 25 mg/70 kg, i.m.) and chlordiazepoxide (25 and 50 mg/70 kg, i.m.) were compared with morphine (15 and 30 mg/70 kg, i.m.) and placebo in their effects on electric shock-induced increases in basal skin conductance. Morphine and chlorpromazine attenuated the increase compared with placebo, while chlordiazepoxide did not. None of the treatments produced reliable effects on the phasic responses to the stimuli.