Background. Pharmaceutical industry funding of psychiatric research has increased significantly in recent decades, raising the question of a relationship between pharmaceutical company funding of clinical psychiatric studies and the outcomes of those studies. This study examines this relationship.

Method. Abstracts of articles from 1992 and 2002 in four peer-reviewed psychiatric journals were examined. Drug outcomes (n=542) for clinical studies were evaluated and then compared across sponsorship source. Outcome raters were blind to source of sponsorship. The percentage of these studies sponsored by drug companies in 2002 v. 1992 was also compared. In a secondary analysis, the contribution of a series of potentially mediating variables to the relationship between sponsorship source and study outcome was assessed via logistic regression.

Results. The percentage of studies sponsored by drug companies increased from 25% in 1992 to 57% in 2002. Favorable outcomes were significantly more common in studies sponsored by the drug manufacturer (78%) than in studies without industry sponsorship (48%) or sponsored by a competitor (28%). These relationships remained after controlling for the effects of journal, year, drug studied, time since FDA drug approval, diagnosis, sample size, and selected study design variables.

Conclusions. These data indicate an association between pharmaceutical industry funding of clinical studies and positive outcomes of those studies. Further research is needed to elucidate the mechanisms underlying this relationship.