Relationships between drug treatment careers and outcomes - Findings from the national drug abuse treatment outcome study

A structural equation modeling approach was used to examine the relationships among characteristics of drug use and treatment careers, length of stay in a current treatment episode, and subsequent drug use among 2,807 clients participating in the Drug Abuse Treatment Outcome Study (DATOS). The model was rested separately for four major modalities. Length of stay in DATOS treatment was significantly related to reduced cocaine use (but not heroin use) during the follow-up period among clients in outpatient drug-free and residential programs and to reduced heroin use (bur not cocaine use) among clients in methadone maintenance. Importantly, longer treatment careers were significantly associated with increased length of stay in DATOS outpatient drug-free programs and were associated with reduced heroin use among clients treated in all modalities except for residential programs; demonstrating cumulative treatment effects. These findings support the notion that treatment effects may accumulate across multiple treatment episodes.