Methods: A quasi-experimental pre-test and post-test design was used to evaluate the impact of the video-assisted teaching module. The study involved 320 secondary school students (ages 14-18) from selected schools in East Tambaram. Pre-test and post-test questionnaires assessed students' knowledge and attitudes regarding substance abuse prevention. Descriptive and inferential statistics, including paired t-tests, were used to analyze the data.

Results: The findings indicated significant improvements in both knowledge and attitudes toward substance abuse prevention after the intervention. A majority of participants demonstrated an increase in knowledge, with 40.6% of students achieving scores in the highest range post-test, compared to only 3.1% pre-test. Attitudes also shifted positively, with a 37.5% increase in students adopting a more positive stance toward substance abuse prevention.