The origin of the psychiatric illnesses observed in drug abusers is often unclear. This study examines the causal relation between drug abuse and specific psychiatric disorders. Fifty-one male veterans first seen in 1972, who were admitted at least once per year for six consecutive years for inpatient drug-abuse treatment, underwent psychiatric assessments at each admission. Eleven men mainly used stimulants, 14 depressants, and 26 opiates. Initial psychiatric examinations showed low symptom levels in all groups but no statistically significant differences among them. By the end of six years, five of the stimulant users had psychoses, and eight of the depressant users had serious depression. The narcotics users showed no change in psychopathology. Differences between the groups were significant at the 0.01 level. These changes were not due to acute toxic reactions, but our data suggest that abuse of particular drugs has a major role in the development of specific psychiatric illnesses. The possibility that different preexisting personality disorders lead to different kinds of drug abuse cannot be excluded. (N Engl J Med 301:1310–1314, 1979) IN the course of evaluating the long-term effectiveness of our drug-abuse treatment program, we discovered a sample of patients who had been initially admitted for inpatient treatment in 1972, and in whom a pattern of virtually continuous drug abuse since then had been punctuated only by readmissions for treatment. The readmission records of these patients provided information on drug-abuse patterns, psychiatric assessments, and personal adjustment over the course of six years. Thus, we had an opportunity to examine the longitudinal relations between patterns of prolonged drug abuse and the development of psychiatric disorders. Methods Subjects The subjects were 51 men. © 1979, Massachusetts Medical Society. All rights reserved.
