Psychiatric Comorbidity in Patients With Substance Use Disorders Attending an Addiction Treatment Center in India Over 11 Years: Case for a Specialized “Dual Diagnosis Clinic”

Objective: Dual diagnosis of substance use disorders and psychiatric illness presents a distinct clinical challenge. These patients have been found to have more complications and poorer outcomes compared to patients with a single disorder only. Data from India are sparse. Methods: The study was a retrospective chart-based review of consecutive patients attending an addiction treatment center in a tertiary care hospital in north India from January 2000 until December 2010. Diagnoses were originally made clinically by face-to-face psychiatric interview and collateral information from family members and were confirmed by consultant psychiatrists following the detailed evaluation. Data on demographics, substance use disorder and psychiatric diagnoses, treatment, and short-term outcomes were extracted from the records. Results: Out of 5,283 patients registered over a span of 11 years, 5,116 (97%) records were available. Of these, 678 (13.2%) had a diagnosis of another non-substance psychiatric disorder. The comorbid psychiatric illnesses included mood disorders (n = 286, 42.2%), psychotic disorders (n = 186, 27.5%), anxiety disorders (n = 113, 16.7%), personality disorders (n = 68, 10.1%), organic disorders (n = 30, 4.5%), and others (n = 31, 4.6%). Alcohol use disorder was significantly more likely to be present with organic, mood, and anxiety disorders. Cannabis use disorder was significantly more likely in the dual diagnosis group as a whole and in particular with psychotic, mood, and personality disorders. Patient attrition from follow-up was substantive, but short-term outcomes among those few who did follow up were favorable. Conclusions: Though the proportion of dual diagnosis patients was relatively low among all patients attending the addiction treatment center, the cumulative number of patients in absolute figures over the years was appreciable. Given the high dropout rates but relatively favorable outcome for those retained in treatment, these patients need special and intensive focus with trained manpower and resources. There is indeed a case for a “dual diagnosis clinic.”