Abstract: There is increasing international recognition that problematic drug and alcohol use is highly prevalent among people with severe mental illness. Such comorbidity is associated with increased frequency of hospitalisation, homelessness and imprisonment. During the 1990's studies from the United States recommended that integrated programmes providing concurrent psychiatric and substance misuse treatment improved patient outcomes. However, it was unclear whether the integration of traditionally separate service delivery systems, and the associated costs of this, was supported by research evidence. In the light of this we conducted a Cochrane review of randomised controlled trials to evaluate the effectiveness of substance misuse treatment programmes within psychiatric care. The review, published in April 1999, found no evidence for any intervention when compared with treatment as usual. This paper will briefly present those findings and discuss the difficulties we, as reviewers, faced when making recommendations for clinicians, consumers and for policy makers. Particular attention will be given to describing the policy environment at the time of the review and the implications this had for our recommendations. The need for reviewers to use language that not only clearly conveys the meaning of their findings, but is also sensitive to the prevalent policy climate, will be discussed.