The use of collateral reports for patients with bipolar and substance use disorders.

This study investigated the value of collateral informant reports of substance use for patients with current bipolar disorder and substance dependence. We collected collateral informant reports on 132 occasions for 32 patients and found a high level of agreement between collateral reports and self-report/urine screen data (75.0%). In only 3 instances did collateral informants report substance use for patients who denied use and had negative urine screens. Frequency of contact between informants and patients was associated significantly with the level of agreement. These findings suggest that obtaining collateral informant data when studying this population may be of limited value.