Diagnostic conundrums in substance abusers with psychiatric symptoms: variables suggestive of dual diagnosis

Patients with substance dependence and psychiatric symptoms often present a diagnostic conundrum because each of these problems may mutually and reciprocally complicate the other. This may challenge the ability to identify dual-diagnosis patients who have both a substance abuse disorder and a definitive symptom-based psychiatric disorder. The main purpose of this explorative study was to identify variables suggestive of dual diagnosis in the population of substance-dependent patients with psychiatric symptoms. A secondary purpose was to examine the subgroups in this population for their distinctiveness from one another. Based upon clinical experience and the literature, seven independent variables were hypothesized as suggestive of dual diagnosis. Seventy-nine patients with substance dependence and psychiatric symptoms of depression, anxiety, and/or psychosis were assessed for symptom and disorder status generating three subgroups: I) 20 patients with psychiatric symptoms not meeting thresholds for clinical significance; II) 36 patients exhibiting a psychiatric disorder (dual diagnosis); and III) 23 patients with psychiatric symptoms meeting thresholds for clinical significance but not for a disorder. Odds ratios were calculated to examine the risk for dual diagnosis using the seven independent variables. A persistent increased risk for dual diagnosis was observed in patients who were positive for the seven variables. The seven variables were combined into an overall measure of patients' risk for dual diagnosis. Mean scores were significantly different for the three groups F(2, 76) = 8.4, p < .001. This study indicates variables that may be suggestive of dual diagnosis and finds subgroup distinctiveness in this sample. Both of these findings have treatment implications.