Use of alcohol and addictive substances by human juveniles and adolescents is common. Animal models offer researchers unique insight into the effects of alcohol and drugs on adolescents. Recent work in rat indicates that periadolescent substance use may disrupt normal pubertal development and may induce stronger effects on system subserving plasticity and cognition than in adults. Several processes may influence the adolescent risk of neurocognitive damage. The brain goes through various dynamic changes during adolescence and can seriously affect the short term growth process. The features of the adolescent brain may in fact predispose a youngster to behave in ways that place him or her at particular risk of experimenting with alcohol or other drugs. In addition to behavioral and neurochemical changes, a number of important physiological alterations occur during adolescence, including changes in brain regions implicated in the reinforcing properties of alcohol and other drugs of abuse. Damage during early stages can cause long term damage which is irreversible. The present review discusses the neurobehavioral, neurochemical and neuroendocrinal effects of alcohol and other drugs of abuse on the adolescent brain in rats.