Relationship between subjective effects and drug preferences: ethanol and diazepam.

The relationship between subjective effects and drug preferences in normal volunteers was explored in a meta-analysis of several previously published studies. Subjective effects of, and preference for, ethanol and diazepam vs. placebo were measured using a choice procedure. Subjects were grouped according to their drug choices: 'non-choosers' never chose drug, whereas 'choosers' always chose drug. The two groups were compared on their subjective responses to drug and on demographic variables. Ethanol decreased Arousal, Elation, Positive Mood and Vigor, and increased Anxiety, Depression and Fatigue in the non-choosers, whereas it increased Arousal and Vigor in the choosers. Ethanol choosers were also more likely to be males and/or full-time students than non-choosers. Diazepam produced sedative-like effects in both choosers and non-choosers, but markedly decreased Anxiety and increased Friendliness in choosers only. Diazepam choice was also associated with more frequent recreational use of marijuana and stimulants. Thus, both demographic variables and subjective drug effects were related to drug preference.