Background:Dual diagnosis is a special case of psychiatric comorbidity in which the drug dependent patient also qualifies for other than dependence co-occurring mental health disorder. This old term is still maintained in bibliography in order to underline the difficulties in treating these patients. Dual diagnosis was found to negatively affect prognosis in patients with drug dependence. Nowadays, the treatment model for dual diagnosis has transformed its focus, from treating each disorder in independent setting to providing integrating care in one setting. The aim of this study was to explore whether dual diagnosis is related with worse prognosis than simple drug dependence, even when integrative care is provided. Methods: Fourty-five consecutive patients (30 males, mean age 27.5 Â± 6.7, 15 females, mean age 26.4 Â± 4.1), 16 of them were dually diagnosed, were admitted to a therapeutic community inspired, abstinence oriented, relapse prevention and rehabilitation program. Integrative care was provided in the sense that both diagnoses were managed by the same multidisciplinary team. Retention in the treatment was used as the endpoint for comparisons. Results: By using time-to-event analysis differences revealed in time to relapse between the group of dually diagnosed and the group with drug-dependence only. (Log Rank Mantel-Cox test shown Chi-Square: 4.52, df=1, p< .05). Univariate and multivariate Cox-regression analysis was conducted and did not show any significant effects of gender, age, multiple-drug dependence, on time to relapse. Conclusion: This study adds evidence to the fact that drug dependent patients with a comorbid mental health disorder show worse prognosis. Treating these dually diagnosed populations according to the integrative care model seems to have advantages in comparison to the previous model of treating each disorder in independent settings, namely a relapse prevention and rehabilitation program and an inpatient or outpatient mental health clinic. Despite these advantages, our findings underline the fact that dual diagnosis is still characterised by a higher relapse rate, even when treatment is provided according to a modern, integrative care model.