Experts have learned that addiction to drugs is a disease that has genetic as well as environmental triggers. The gene involved in controlling dopamine, the brain’s pleasure chemical, is one factor. Children of alcoholics are three times as likely to become alcoholics themselves; identical twins exhibit co-dependence factors. People with co-morbid psychiatric disorders are also at higher risk. From the series The Human Condition. Copyright 2001. www.intelecomstore.org.