Genetic factors in drug abuse and dependence.

The etiology of drug abuse/dependence is a complex interplay of psychosocial and biological factors. These factors include socioeconomic status, education, drug availability, peer pressure, childhood and adult comorbid psychiatric disorders, and specific mutant genes. The emphasis of this chapter is on the role that genetic factors play in an individual's vulnerability to drug abuse/dependence, henceforth simply referred to as drug abuse. One major point is that there are no genes unique to causing drug abuse. Instead there are genes that alter the normal function of the central nervous system as manifested by a wide range of interrelated impulsive, compulsive, addictive, affective, and anxiety behaviors. One of the outcomes or associated behaviors of attempting to cope with these disorders is substance abuse. In this light, the genetics of any one of these interrelated behaviors has relevance to drug abuse. Drug abuse is not an island unto itself.