How Effective Is Drug Therapy in Treating Anxiety and Comorbid Alcohol Use Disorders?

While anxiety disorders frequently co-occur with alcohol dependence, few studies have examined the effects of pharmacotherapy in improving treatment response and reducing symptoms in patients with anxiety disorders that are comorbid with substance use disorders. In an article published in the Cochrane Library, researchers sought to examine the available evidence for the effectiveness of certain medications in the treatment of anxiety disorders and comorbid alcohol use disorders.

Five clinical trials involving 290 patients were included in the review; patients were diagnosed with alcohol use disorders and had one of the following anxiety disorders: post-traumatic stress disorder (two studies), social anxiety disorder (two studies), and generalized anxiety disorder (one study). Medications assessed in these trials included selective serotonin re-uptake inhibitors (sertraline, paroxetine) and buspirone; treatment duration ranged from eight to 24 weeks.

The following is a summary of findings:

• Although global clinical response (using the Clinical Global Impressions-Improvement scale) was seen in more than twice as many patients receiving paroxetine than with placebo (57.7% vs. 25.8%, respectively), researchers considered the evidence for this finding to be of very low quality due to the small number of studies.  
• In one study, buspirone appeared to be superior to placebo in reducing anxiety symptom severity over 12 weeks, but efficacy was not seen for paroxetine.
• In another study, paroxetine was as effective as desipramine, a tricyclic antidepressant, in reducing post-traumatic stress disorder symptom severity.
• With regards to abstinence from alcohol, there was no evidence to show that alcohol use was responsive to any of the study medications.
• Treatment discontinuation due to adverse effects was high, with 43.1% of patients withdrawing from medication, although there was very low quality evidence that paroxetine was well tolerated.

Based on the findings of this study, the authors state that evidence for effective treatment of anxiety disorders and comorbid alcohol use disorders is inconclusive and that larger studies would need to be conducted to truly assess the effectiveness of pharmacotherapy in these patients. Since the majority of the data involves SSRI use, further research should be conducted on other medication classes as well as patient subgroups.