Advances in research of the neurobiology of addictive disorders have provided clinicians with an evolving perspective on addiction. All drugs of abuse seem to share a common neurobiologic substrate involving the mesocorticolimbic system. Considerable evidence shows that these dopaminergic projections are involved in the positive brain reward, which drives addictive disorders; however, recent studies also implicate the neurotransmitters glutamate and serotonin in learning and sensitization to drug use. A review of the neurobiology of tobacco smoking provides further examples of the mechanisms for reinforcing tobacco use, including the enhancement of memory and treatment of depression with nicotine and MAO-inhibiting chemicals in tobacco smoke respectively. The relevance of these advances may be realized through the destigmatization of addictive disorders and the development of new and improved treatment strategies.