Modafinil augmentation of antidepressant treatment in depression

Despite a relative lack of controlled data, stimulants are often used to augment antidepressant treatment in patients who have had only a partial response to first-line therapy. Modafinil is a novel psychostimulant that has shown efficacy in, and was recently marketed for, treating excessive daytime sleepiness associated with narcolepsy. The mechanism of action of modafinil is unknown, but, unlike other stimulants, the drug is highly selective for the central nervous system, has little effect on dopaminergic activity in the striatum, and appears to have a lower abuse potential.

In this retrospective case series, we describe 7 patients with DSM-IV depression (4 with major depression and 3 with bipolar depression) for whom we used modafinil to augment a partial or nonresponse to an antidepressant. The Hamilton Rating Scale for Depression was administered as part of routine clinical practice prior to treatment and at each subsequent visit.

At doses of 100 to 200 mg/day, all 7 patients achieved full or partial remission, generally within 1 to 2 weeks. All patients had some residual tiredness or fatigue prior to starting modafinil, and this symptom was particularly responsive to augmentation. Side effects were minimal and did not lead to discontinuation of the drug in any of the patients.

Modafinil appears to be a drug with promise as an augmenter of antidepressants, especially in patients with residual tiredness or fatigue. It is a particularly attractive alternative to other stimulants because of its low abuse potential and Schedule IV status.