Résumé
To determine frequency of substance abuse and the commonest substance of abuse among medical and non-medical undergraduates. Survey report. Dow International Medical College, Karachi, from June 2012 to August 2012. Semester VIII students from Dow International Medical College, Dow University of Health Sciences who visited the selected medical and non-medical universities, data collected through self responding questionnaire which was handed out to the participants. Data was collected from 4 medical and 4 non-medical universities. All responding undergraduate students in selected universities were included. Data was maintained and analyzed on SPSS version 16 for descriptive statistics. Total number of responders was 572 with male: female ratio of 1.23: 1.0 and mean age of 21.76 +/- 2.168 years. Frequency of regular substance abuse was 20.1%. Males were abusing substance more than females, ratio being 4.7: 1.0 among abusers. The most common substance of abuse was tobacco. Frequency of regular substance abuse in nonmedical undergraduates was 29.4% which was higher than medical graduates [13.4%]. Substance abuse among undergraduates in selected universities in Karachi was overall 20.1%. Male nonmedical undergraduates were more frequently using such substances; tobacco being the most common