Morning Light Treatment Hastens the Antidepressant Effect of Citalopram: A Placebo-Controlled Trial

Background: Selective serotonin reuptake inhibitors are effective in approximately 70% of patients with a major depressive episode, but therapeutic changes usually require 2 weeks of administration to become clinically relevant. Adjunct light therapy has been proposed to hasten the effects of drug treatment. The purpose of the present study was to evaluate the effect of morning light therapy or placebo combined with citalopram in the treatment of patients affected by a major depressive episode without psychotic features.

Method: Thirty inpatients (DSM-IV major depressive disorder [N = 21] and bipolar disorder [N = 9]) were treated with citalopram, 40 mg, and randomized in a 3:2 manner to receive 30 minutes of 400 lux green light treatment in the morning or placebo (exposure to a deactivated negative ion generator) during the first 2 weeks of drug treatment. Timing of light therapy was individually defined to obtain a 2-hour phase advance to morning light. Outcome was measured with the Hamilton Rating Scale for Depression and the Zung Self-Rating Depression Scale every week, and with a Visual Analogue Scale 3 times a day during the first week.

Results: All outcome measures showed significantly (p < .05) better mood improvement in light-treated patients, resulting in faster responses to antidepressant treatment.

Conclusion: The combination of citalopram and light treatment was more effective than citalopram and placebo in the treatment of major depression. With an optimized timing of administration, low-intensity light treatment significantly hastened and potentiated the effect of citalopram, thus providing the clinical psychiatrists with an augmenting strategy that was found effective and devoid of side effects.