Drug Treatments for Patients with Dysthymia

Clinical Question

Which drug treatments for dysthymia are most effective?

Evidence-Based Answer

All antidepressants studied have similar efficacy in the treatment of patients with dysthymia. Side effect profiles vary. The largest comparisons support the use of tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs).

Practice Pointers

Patients with dysthymia have less severe but more chronic symptoms than patients with depression. De Lima and colleagues published two systematic reviews^1,2 on the treatment of dysthymia. The first review, by De Lima and Moncrieff,¹ found that antidepressants are highly effective in treating dysthymia compared with placebo. Approximately four patients must be treated to achieve one response. However, it is not clear which antidepressant produces the best results.

To determine the most effective antidepressant, De Lima and Hotopf² searched for randomized and quasi-randomized controlled trials comparing at least two active drug treatments. Patients in these studies had dysthymia for at least two years and were studied for four to 12 weeks in psychiatric, primary care, and community settings.

Tricyclic antidepressants, SSRIs and monoamine oxidase inhibitors had similar efficacy. Imipramine was the most commonly studied tricyclic antidepressant, and fluoxetine was the most commonly studied SSRI. Only one study compared SSRIs with tricyclic antidepressants. Both drug classes had a similar effect on mood, but the SSRIs had a lower dropout rate. Therefore, medication choice should be based on the side effect profile. No data are available on optimal dosage or length of treatment.