Generally, the stage of adolescence comprises between 12-18 years of age. 18-22 years of age is called later adolescence. Adolescence is a period of great stress and strain, storm and strife. Alcohol and other substance use are on the rising trend among the adolescent student. Substance abuse is one of the major health challenges across the globe. Adolescents are among most affected. This study aims to examine the reasons for initiation, maintenance of harmful use of substances among adolescents or young adults by comprising 50 male and 50 female students who are studying B.A. 3rd semester aged 18-22 years were selected through random sampling method. It was found that most of the male adolescent students are using substance than the female adolescent student. Both male and female adolescent student had specific personal reasons for their respective behavior. Adolescents would use substance for various psychological reasons despite knowing the harmful effects of substance.