A profile analysis of adolescents with a drug dependence of hallucinogen, methamphetamine, and cannabis using the scales of the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A) found significant differences between hallucinogen and cannabis groups of adolescents on the Hypochondriasis (Hs), Schizophrenia (Sc), and Adolescent-Bizarre Mentation (A-biz) scales. Scores on all scales of the methamphetamine group were not significantly different from scale scores on the cannabis or hallucinogen groups. Research has shown that many adolescents turn to licit or illicit drugs for a variety of reasons, such as a lack of parental support, social support, or peer pressure. This study is one of the first to utilize personality assessment to differentiate personality characteristics of adolescents reporting the specific use of hallucinogen, cannabis, or methamphetamine as a drug of choice. The study consisted of 60 adolescents evenly distributed for hallucinogen (n = 20), cannabis (n = 20), and methamphetamine (n = 20) use. It was hypothesized that the hallucinogens group would have a significantly higher Adolescent-Bizarre Mentation (A-biz) Content scale score than other groups. In addition, it was hypothesized that for methamphetamine users, the Paranoia (Pa) scale would be higher than the hallucinogen and marijuana groups. Tables, references