Treatment process components and heroin use outcome among methadone patients.

The study proposes and tests an integrative and directional (structural equations) model to explain how pre-treatment motivation, frequency and content of counselling services, programme perceptions, and methadone dose are related to 1 and 6 months heroin use outcomes among opiate addicts receiving outpatient methadone treatment. Data were collected as part of the National Treatment Outcome Research Study (NTORS). The sample comprised 262 patients who were admitted to, and retained in methadone treatment programmes at 6 months. Structural equation models showed several relationships between treatment process variables and heroin use outcomes at 1 and 6 months follow-up. Programme perceptions and methadone dose were related to reduced heroin use at 1 month; early engagement with treatment services was related to reduced heroin use at 6 months. Pre-treatment motivation and engagement with treatment services were indirectly related to reduced heroin use at 1 month through their association with programme perceptions. Short-term (1 month) heroin use was strongly related to heroin outcome at 6 months. In addition to direct effects, treatment factors may have important indirect effects upon subsequent outcomes through their influence upon short-term outcomes.