Single-blind, placebo phase-in trial of two escalating doses of selegiline in the chronic fatigue syndrome

Neuropsychobiology. 1998;37(3):150-4. doi: 10.1159/000026494.


Aim: To perform a clinical trial of selegiline in 25 patients with chronic fatigue syndrome (CFS) where patients were told they would receive placebo or active agent at different times during the 6-week trial. We chose selegiline, a specific monoamine oxidase (MAO) B receptor inhibitor, because a prior trial of lowdose phenelzine, a nonspecific MAO inhibitor, showed a small but significant therapeutic effect.

Methods: Questionnaires comprised of 19 tests of mood, fatigue, functional status and symptom severity were collected at the start and end of the trial as well as 2 weeks after its start. The trial was done in three 2-week blocks: in the first, 2 placebo pills were given per day; in the next, one 5-mg tablet of agent and one placebo were given per day, and in the last, a 5-mg tablet of agent was given twice a day. The plan was to compare the changes in the 19 tests during the placebo phase to those found in the active treatment phase in 19 patients completing the trial.

Findings: Significant improvement in 3 variables-tension/anxiety, vigor and sexual relations-was found. A significant pattern of improvement compared to worsening was found for the 19 self-report vehicles during active treatment as compared with placebo treatment. Evidence for an antidepressant effect of the drug was not found.

Conclusions: Selegiline has a small but significant therapeutic effect in CFS which appears independent of an antidepressant effect.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living / classification
  • Activities of Daily Living / psychology
  • Affect / drug effects
  • Drug Administration Schedule
  • Fatigue Syndrome, Chronic / diagnosis
  • Fatigue Syndrome, Chronic / drug therapy*
  • Fatigue Syndrome, Chronic / psychology
  • Humans
  • Monoamine Oxidase Inhibitors / administration & dosage*
  • Monoamine Oxidase Inhibitors / adverse effects
  • Neuroprotective Agents / administration & dosage*
  • Neuroprotective Agents / adverse effects
  • Selegiline / administration & dosage*
  • Selegiline / adverse effects


  • Monoamine Oxidase Inhibitors
  • Neuroprotective Agents
  • Selegiline