The effect of co-morbid depression and anxiety on the course and outcome of alcohol outpatient treatment: a naturalistic prospective cohort study

Background: Studies examining the effect of alcohol treatment among patients with alcohol use disorders (AUD) and co-morbid depression and/or anxiety are few and show inconsistent, but mainly negative drinking outcomes. Aims: To describe the prevalence of anxiety and depression among Danish patients seeking treatment for an AUD, and to investigate the infl uence of psychiatric co-morbidity on the course and effect of treatment. Method: A consecutive sample
of 363 outpatients with an AUD diagnosis according to the ICD-10 Diagnostic Criteria for Research was assessed by the means of the Addiction Severity Index at treatment start and 276 (76%) followed up after 1 year. Results: 15.7% of the patients suffered from depression and 12.7% from anxiety at baseline. Both patients with or without co-morbidity had improved on drinking outcome measures at follow-up with medium to large effect sizes. No difference was
found between patients with and without co-morbidity. Conclusion: In contrast to the majority of prior studies, this study provides evidence that depression and anxiety do not have an effect on alcohol treatment. However, because of the naturalistic setting, a number of limitations should be taken into consideration interpreting the results.