Duloxetine for the Treatment of Dysthymia

The purpose of this research is to obtain information on the safety and effectiveness of duloxetine (Cymbalta) in the treatment of dysthymia. Duloxetine has been approved by the federal Food and Drug Administration for the treatment of depression. The use of duloxetine for treatment of dysthymia is considered experimental.

Dysthymia is defined as chronic, low-grade depression, characterized by feeling low or depressed, that lasts for two or more years. Additional symptoms may include: poor appetite or overeating; insomnia or sleeping too much; low energy or fatigue; low self-esteem; poor concentration or difficulty making decisions; and feelings of hopelessness.

Dysthymia affects 3-6% of the general population, but is an underdiagnosed and undertreated disorder. In double-blind, placebo-controlled clinical trials of antidepressant medications, dysthymia response rates are around 60%, compared to an average placebo response rate of about 30%. Duloxetine has not been studied in the treatment of dysthymia, but has shown results in the treatment of major depression. In a 9-week, double-blind, placebo-controlled study of 257 patients with major depression, 65% responded to duloxetine 60mg/day, compared to 43% to placebo. Based on these results, it is highly likely that duloxetine will be an effective treatment for dysthymia.

This research study is being conducted at Stanford University Medical Center with a total of 24 patients, age 18 and above, with dysthymia.

In the study, subjects will receive duloxetine for 12 weeks. This is an open-label study, which means that every subject receives the study medication.

In total, subjects are seen for 10 visits across 13 weeks. At each visit subjects' heart rate, blood pressure and weight measurements will be obtained. At each visit study personnel will interview subjects about their symptoms, monitor side effects and ask them to complete study questionnaires.

Beginning at the second visit, subjects receive duloxetine 60 mg/day. If they experience side effects, the dose can be decreased to 30 mg/day for several days, but will be increased back to 60 mg/day by the end of the first week. If subjects are unable to tolerate a dose of 60 mg/day due to side effects, they will be withdrawn from the study. At the end of 6 weeks, if they have not responded to the study medication (as determined by doctor ratings based on subjects' reports), the dose of duloxetine will be increased to 120 mg/day, unless subjects are experiencing troubling side effects. Subjects continue on the minimum dose that brings about remission or the maximum tolerated dose for the remaining 6 weeks. Medication dosing will be flexible and determined by tolerance (side effects) and therapeutic effect.