Benefits and risks of pharmacotherapy for dysthymia: a systematic appraisal of the evidence.
BACKGROUND
Dysthymia is a prevalent form of subthreshold depressive disorder, associated with considerable disability and high co-morbidity. This paper systematically appraises the evidence for the efficacy and acceptability of the pharmacological treatment for this condition.


METHODS
Randomised, controlled trials evaluating the efficacy of drug therapies for dysthymia were included. A comprehensive search of the literature was performed, aiming to avoid publication bias. Pooled relative risks (RR) and 95% CIs were calculated with the Random Effect Model method. The number needed to treat (NNT) and number needed to harm (NNH) were estimated for statistically significant results.


RESULTS
Twenty-five trials were included for the main comparisons. Regarding placebo-controlled trials (n = 16), similar results were obtained in terms of efficacy for different groups of drugs, such as tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), monoamine oxidase inhibitors (MAOIs) and other drugs (sulpiride, amineptine, and ritanserin). The pooled RR for treatment response was 0.68 (95% CI 0.57-0.81) for TCA and the NNT was 4.3 (95% CI 3.2-6.5); 0.68 (95% CI 0.56-0.82) for SSRIs (NNT 5.1; 95% CI 3.9-7.7); 0.59 (95% CI 0.48-0.71) for MAOIs (NNT 2.9; 95% CI 2.2-4.3). Other drugs (amisulpride, amineptine and ritanserin) showed similar results. The equivalent efficacy between antidepressants as found in trials where active medications were compared confirmed the efficacy findings from placebo trials. In general, patients treated with a TCA were more likely to report adverse events, compared with placebo and SSRIs.


CONCLUSIONS
Pharmacotherapy for dysthymia appears to be an effective short-term treatment for dysthymic disorder. Newer antidepressants are equally effective and have better acceptability than TCAs, although their higher cost must be balanced against this assumed advantage.
De Lima
Maurício S
MS
Universidade Federal de Pelotas, Rio Grande do Sul, Brazil. mslima@terra.com.br
Hotopf
Matthew
M
D000928:Antidepressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000929:Antidepressive Agents, Tricyclic / Q000627:therapeutic use; D003986:Dibenzocycloheptenes / Q000627:therapeutic use; D019263:Dysthymic Disorder / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D008996:Monoamine Oxidase Inhibitors / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D016713:Ritanserin / Q000627:therapeutic use; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use; D013469:Sulpiride / Q000627:therapeutic use; D016896:Treatment Outcome
D000928:Antidepressive Agents; D000929:Antidepressive Agents, Tricyclic; D003986:Dibenzocycloheptenes; D008996:Monoamine Oxidase Inhibitors; D016713:Ritanserin; D017367:Selective Serotonin Reuptake Inhibitors; D013469:Sulpiride; C011597:amineptin