A third possible explanation for the null relationship between psychiatric morbidity and cocaine dependence severity is that the relatively low self-reported levels of recent cocaine use by two-thirds of the sample suggest that this non-clinical sample is comprised primarily of individuals in recovery from cocaine dependence, with a sub-group still dependent. The finding that almost two-thirds have been in self-help support programs and one-third in treatment is consistent with this view, suggesting that a majority of study participants have been able to get help for their cocaine dependence. For the participants currently in remission, their self-reports of cocaine dependence severity are not only retrospective but may involve a gap of several years, and thus may be insensitive to potential exacerbating factors such as psychiatric disorders. The fact that psychiatric morbidity was assessed lifetime rather than currently raises the possibility that the psychiatric disorders also may have improved or been in remission. Thus, this sample may have under-represented the sub-group of actively cocaine dependent persons with current psychiatric illnesses, and it is possible that these are the cocaine dependent adults for whom psychiatric morbidity may have the greatest impact on cocaine dependence severity.
