The first group are those adolescents most likely to be in trouble with the law or at school, and who present the most blatant behavior problems. The following two groups are those most likely to be less visible and unnoticed; these adolescents include those most likely to commit suicide. The fourth group is comprised of adolescents who are least likely to be diagnosed as chemically dependent or otherwise deviant, who represent the highest level of functioning, and whose parents are most likely to be in greatest denial. These typologies are based on the following variables: drinking/drug use pattern; goal of substance use; behavior when drinking, intoxicated, or drug-affected; psychological functioning; characteristic patterns of social interaction and behavior; school performance; family dynamics; identified role as child of an alcoholic or previous psychiatric diagnosis; and most effective treatment strategies. 3 notes (Author abstract modified)