• Alliance;
  • retention;
  • review;
  • treatment outcomes


Background  In the past two decades, a number of studies investigating the role of the therapeutic alliance in drug treatment have been published and it is timely that their findings are brought together in a comprehensive review.

Aims  This paper has two principal aims: (1) to assess the degree to which the relationship between drug user and counsellor predicts treatment outcome and (2) to examine critically the evidence on determinants of the quality of the alliance.

Methods  Peer-reviewed research located through the literature databases Medline, PsycInfo and Ovid Full Text Mental Health Journals using predefined search-terms and published in the past 20 years is considered. Further papers were identified from the bibliographies of relevant publications.

Findings  A key finding is that the early therapeutic alliance appears to be a consistent predictor of engagement and retention in drug treatment. With regard to other treatment outcomes, the early alliance appears to influence early improvements during treatment, but it is an inconsistent predictor of post-treatment outcomes. There is relatively little research on the determinants of the alliance. In studies that are available, clients’ demographic or diagnostic pre-treatment characteristics did not appear to predict the therapeutic alliance, whereas modest but consistent relationships were reported for motivation, treatment readiness and positive previous treatment experiences.

Conclusions  The therapeutic alliance plays an important role in predicting drug treatment process outcomes, but too little is known about what determines the quality of the relationship between drug users and counsellors.