Clinicians' impact on substance use disorder treatment has been much less s
tudied than therapy and patient variables. Yet, in this selective review of
literature, a growing body of empirical work on clinicians' impact highlig
hts several key issues that have relevance both to clinical practice and fu
ture research. These issues include clinicians' effect on treatment retenti
on and outcome, professional characteristics, recovery status, adherence to
protocols, countertransference, alliance, personality, beliefs about treat
ment, and professional practice issues. Specific recommendations are offere
d to help improve the quality of care clinicians provide. In particular, it
is suggested that greater accountability for clinicians' performance be ba
lanced with increased support for their very difficult role. Methodological
issues in studying clinicians are also addressed.