SINCE THE BRAIN retains memories of pleasurable feelings, even after people have successfully completed treatment they often retain the desire to abuse chemicals. When former substance abusers submit to this desire and abuse chemicals only one time, they are said to have slipped up. When the abuse continues, they are said to have experienced a relapse. Approximately 50 percent of all chemically dependent people relapse at least once after going through treatment, and it is not uncommon for addicts to experience five relapses before recovering completely. Experts say that relapses are often triggered by a number of psychological and visual cues that remind the brain of the pleasurable sensations of substance abuse, reactivating an urge for drugs or alcohol. These cues vary from person to person, but generally include contact with drugs or alcohol, or with people, activities, and feelings that encouraged the...