The coexistence of obsessive-compulsive symptoms (OCS) and obsessive-compulsive disorder (OCD) and substance use disorders (SUD) is an understudied area. Psychoactive drug use is increasingly prevailing among young people, which has a serious impact on our society but there are concerns that psychoactive drugs may be associated with psychiatric symptoms or psychobiological problems. There are converging lines of evidence demonstrating that SUD coexist with OCD or OCS with high prevalence. The mutual impact of substance abuse and OCD on the severity of each other and the lines of management postulated for such comorbidity have received much recent attention in the literature.