Personality characteristics and lifestyle variables were assessed in two cohorts of second-year medical students at the University of Newcastle upon Tyne, UK as part of a psychopharmacology 'teach-in' in 1993 and 1994. The pooled sample included 186 students: 77 men, 109 women, mean age 20.4 +/- 1.8 years. Measures included the Eysenck Personality Questionnaire, the Hospital Anxiety Depression Scale, and a questionnaire concerning consumption of alcohol, tobacco, cannabis and other illicit drugs, and physical exercise. The results were compared, where possible, with a similar survey in Newcastle upon Tyne medical students in 1983 and 1984. Personality variables, prevalence of cigarette smoking, levels of caffeine consumption and participation in sports had not changed significantly over the decade. There appeared to be a modest overall increase in alcohol consumption and in the 1993 and 1994 cohorts of students, 25.5% of those who drank alcohol exceeded recommended low risk levels (comparable data not available for 1983 and 1984). Reported use of cannabis and other illicit drugs had more than doubled, and in the present survey 49.2% of students recorded using cannabis and 22% had tried other illicit drugs. Corresponding figures for 1983 and 1984 were 20.9% for cannabis and 3.3% for other illicit drugs. Anxiety levels were not measured in 1983 and 1984 but in the present survey 39.3% of the students had anxiety ratings within the clinically significant range. The high levels of alcohol consumption and illicit drug use, and the high anxiety ratings, in this sample of medical students are a cause for concern.(ABSTRACT TRUNCATED AT 250 WORDS)