CRD summary

This review assessed the treatment of depression in patients with alcohol or other drug dependence. The authors concluded that antidepressant medication has a modest beneficial effect for patients with combined depressive and substance use disorders. The conclusions are based on a well-conducted review with good-quality studies, but it should be noted that not all of the studies showed a beneficial effect.

Authors' objectives

To assess the efficacy of antidepressant medications for the treatment of combined depression and substance use disorders.

Searching

PubMed, MEDLINE and the Cochrane library were searched from 1970 to December 2003 for publications in any language; the keywords were reported. In addition, the reference lists of key publications and reviews were screened and experts in the field were contacted.

Study selection

Assessment of study quality

The reviewers used two published scales to assess the validity of the studies: a 15-item quality scale addressing methodology and reporting of the trials with regard to randomisation, blinding, sample selection, therapeutic regimen, outcome measures, statistical analysis; and one guideline rating the adequacy of the allocation concealment, the method of generating the sequence of allocation and blinding. Two reviewers independently rated the quality of the studies.

Data extraction

One reviewer extracted the data and a second reviewer checked them, with any discrepancies being resolved by consensus. With regard to depression, the standardised difference between mean HDS scores was extracted or computed from the F-test in covariance analyses, or from means and standard deviations (SDs) or the significance level. Intention-to-treat data or the most complete sample were used for analysis. With regard to substance use, the standardised difference between means was calculated from raw means and SDs, or estimated from graphs. Where several measures were available, average effect sizes were used. Categorical measures of depression and substance abuse were also extracted.

Methods of synthesis

Results of the review

Fourteen trials (n=848) were included in the review.

The included trials were of moderately high quality: all studies were rated adequate for allocation concealment, method of randomisation and blinding.

The pooled effect size for improvement in depression was 0.38 (95% CI: 0.18, 0.58), showing a small to medium effect of the antidepressant treatment compared with placebo (14 studies). However, the results of the individual studies were statistically heterogeneous (P<0.02), with 6 studies showing no benefit of the treatment (effects ranged from -0.21 to 1.07).

The pooled effect size for improvement in substance use was 0.25 (95% CI: 0.08, 0.42), based on 13 studies. The results in the individual studies ranged from -0.27 to 0.81 and significant statistical heterogeneity was found (P<0.15).

Studies with larger effect sizes for depression showed more improvement with regard to the quantity of substance use, but sustained abstinence rates were low. Studies with low placebo response showed larger effects, and diagnostic methods and concurrent psychosocial interventions seemed to influence the results.

There was little indication of publication bias.

Authors' conclusions

Antidepressant medication exerted a modest beneficial effect for patients with combined depressive and substance use disorders. The authors also stressed that concurrent therapy targeting the addiction was also indicated.

CRD commentary

This was a review with a clear question and strict inclusion criteria. The search showed efforts to identify relevant published and unpublished data and the potential for publication bias was investigated. Measures were taken to reduce errors and bias in the selection and quality rating of the studies. The studied outcomes were not objective measures, but the fact that only double-blinded RCTs were included in the review will have reduced bias in favour of the treatment.

The review provided a pooled effect size across all of the included studies, which proved to be heterogeneous with regard to depression. Factors influencing the treatment effects were also investigated and significant moderators were detected. The sample sizes of the identified studies were small, but they seemed to be of good or sufficient quality. The authors' conclusions that antidepressant medication exerted a modest beneficial effect are likely to be reliable, but it should be noted that not all of the studies showed a beneficial effect.

Implications of the review for practice and research

Practice: The authors stated that specific interventions targeting addiction are necessary, but these should not detract from the importance of treating the depression in patients with concurrent depression and alcohol or other drug dependency. Efforts to differentiate depression and substance-related depressive symptoms should be made.

Research: More research is needed to analyse variations in the strengths of the effect of treating depression when differentiating depression and substance-related depressive symptoms.

Funding

National Institute on Drug Abuse, grant numbers P50 DA09236, K02 DA00288 and K02 DA00465; New York State Psychiatric Institute.

Bibliographic details

Nunes E V, Levin F R. Treatment of depression in patients with alcohol or other drug dependence: a meta-analysis. JAMA 2004; 291(15): 1887-1896. [PubMed: 15100209]

Original Paper URL

http://jama.ama-assn.org/

Indexing Status

Subject indexing assigned by NLM

MeSH

Alcoholism /complications /therapy; Antidepressive Agents /therapeutic use; Depressive Disorder /complications /drug therapy; Humans; Substance-Related Disorders /complications /therapy; Treatment Outcome

AccessionNumber

12004008251

Database entry date

30/09/2005

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.