Objectives. Using an epidemiologically obtained sample, we examined patterns of illicit drug use, abuse, and remission over a 25-year period and recent treatment use. Methods. The surviving members of the cohort (n = 841), previously surveyed in 1972 and 1974, comprised 3 subsamples of Vietnam War enlisted men and civilian controls. Retrospectively obtained year-to-year measures from the 1996-1997 survey included use and remission of sedatives, stimulants, marijuana, cocaine, and opiates, as well as substance abuse and psychiatric treatment use. Results. Relatively stable patterns of frequent use in adulthood were found, with the mean duration from initiation to the last remission ranging from 9 to 14 years. A majority attempted to quit; however, most did not use traditional drug treatment in their last attempts. Fewer than 9% of the then-current drug users were treated in inpatient or outpatient settings at the time of data collection. Conclusions. Most drug abusers who had started using drugs by their early 20s appeared to gradually achieve remission. Spontaneous remission was the rule rather than the exception. Nonetheless, considerable unmet needs existed for those who had continued use into middle age.