Given the stimulating effect of cocaine, it mainly affects the brain. When cocaine enters the bloodstream, it activates the production of dopamine. High dopamine levels increase the pleasure and reward effects in other parts of the body. The chemical components of cocaine also block the return of dopamine to the brain and prolong the duration of the high effects. Continued euphoria could impair the brain and make it tolerant of cocaine. Long-term teen cocaine use leads to addiction and dependence. The effects are fatal for adolescents, as their minds are still developing.