Although the use of drugs by medical students is not different from that of the majority of other college students, they will be the professionals in charge of diagnosing and treating dependence in the future. The objective of this study is to describe evolutional patterns of drug use in a distinguished Brazilian medical school(UNIFESP). Different patterns might guide preventive strategies tailored for specific sub-groups of students.

Recent use of psychoactive substances among 456 medical students throughout the six grades was surveyed by way of a self-report questionnaire using World Health Organisation criteria.

Among male medical students, the most frequently used substances were alcohol (80.5 %), cannabis (25.3 %), solvents (25.2 %), and tobacco (25.2 %), whereas among female students the most frequently used drugs were alcohol (72.6 %), tobacco (14.6 %), solvents (10.5 %), and tranquillisers (7.5 %). Male students showed a progressively increasing use of cannabis from the first (13.6 %) to the fourth (38.4 %) academic years. Contrastingly, the proportion of female students using cannabis markedly decreased during the same period (12.9 % to 0%), although they reported at the same time an increasing proportion of tranquilisers use (from 3.4% to 11.1 %). Switch from illegal to legal drugs were observed only among female students. Male students tended to alternate cannabis and solvents throughout college years.

Interventions aiming to influence patterns of drug consumption among medical students must consider both gender differences and evolutional patterns of substance use throughout medical course.