Drug treatments for dysthymia

Many drug treatments have been proposed for the treatment of dysthymia. There is a need to know whether the different classes of antidepressants have similar efficacy. The tolerability of treatments may be even more important, since dysthymia is a chronic condition characterised by less severe symptoms than major depression. A total of 14 trials were included in this review. All drugs promoted similar clinical responses, although with different side effect profiles. There are no significances differences in efficacy between different classes of antidepressants in the treatment of dysthymia, although side effect profiles may be different. The evidence for TCAs and SSRIs was the most robust. The conclusion is that the choice of drug must be made based on consideration of drug-specific side effect properties.

Authors' conclusions: 

The conclusion is that the choice of drug must be made based on consideration of drug-specific side effect properties.

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Background: 

Many drug treatments have been proposed for the treatment of dysthymia, but with so many potential comparisons it is not possible at the present time to determine which is the treatment of choice. There is a need to know whether the different classes of antidepressants have similar efficacy. In addition, the tolerability of treatments may be even more important, since dysthymia is a chronic condition characterised by less severe symptoms than major depression.

Objectives: 

To conduct a systematic review of all randomised controlled trials comparing two or more active drug treatments for dysthymia.

Search strategy: 

Electronic searches of Cochrane Library, EMBASE, MEDLINE, PsycLIT and LILACS, Biological Abstracts; reference searching; personal communication; unpublished trials from pharmaceutical industry.

Selection criteria: 

Only randomised and quasi-randomised controlled trials were included. Trials had to compare at least two active drug treatments in the treatment of dysthymia. Exclusion criteria were: non-randomised studies, studies which included patients with mixed major depression/dysthymia and studies on depression/dysthymia secondary to other disorders (e.g. substance abuse).

Data collection and analysis: 

The reviewers extracted the data independently and odds ratios, weighted mean difference and number needed to treat were estimated. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption.

Main results: 

A total of 14 trials were eligible for inclusion in the review. All studied drugs promoted similar clinical responses, although with different side effect profiles. The evidence for TCAs and SSRIs was the most robust, considering the number of trials and participants.