TY - JOUR KW - Adolescent KW - Adult KW - Age Factors KW - California/epidemiology KW - Cohort Studies KW - Crime/statistics & numerical data KW - Heroin Dependence/epidemiology KW - Humans KW - Male KW - Middle Aged KW - Proportional Hazards Models KW - Severity of Illness Index KW - Socioeconomic Factors KW - Substance-Related Disorders/epidemiology KW - Time Factors KW - Young Adult AU - B. Nosyk AU - M. D. Anglin AU - M. L. Brecht AU - V. D. Lima AU - Y. I. Hser A1 - AB - In accordance with the chronic disease model of opioid dependence, cessation is often observed as a longitudinal process rather than a discrete endpoint. We aimed to characterize and identify predictors of periods of heroin abstinence in the natural history of recovery from opioid dependence. Data were collected on participants from California who were enrolled in the Civil Addict Program from 1962 onward by use of a natural history interview. Multivariate regression using proportional hazards frailty models was applied to identify independent predictors and correlates of repeated abstinence episode durations. Among 471 heroin-dependent males, 387 (82.2%) reported 932 abstinence episodes, 60.3% of which lasted at least 1 year. Multivariate analysis revealed several important findings. First, demographic factors such as age and ethnicity did not explain variation in durations of abstinence episodes. However, employment and lower drug use severity predicted longer episodes. Second, abstinence durations were longer following sustained treatment versus incarceration. Third, individuals with multiple abstinence episodes remained abstinent for longer durations in successive episodes. Finally, abstinence episodes initiated >10 and 10 and