Effects of Light Therapy on Suicidal Ideation in Patients With Winter Depression

Background: Recent case reports suggest that
some patients with seasonal affective disorder (SAD) may become
suicidal after initial treatment with light therapy. This
retrospective study sought to determine the effects of light
therapy on suicidal ideation in patients with SAD.

Method: The cases of 191 depressed patients with
SAD by DSM-III-R or DSM-IV criteria treated with an open trial of
morning light therapy using cool white fluorescent light boxes
(2500 lux for 2 hours per day or 10,000 lux for 30 minutes per
day) for 2 weeks were retrospectively analyzed. Patients had been
rated before and after treatment with the expanded Hamilton
Depression Rating Scale (SIGH-SAD).

Results: Sixty-seven percent of patients were
rated as clinical responders to light therapy. There was
significant improvement in the SIGH-SAD suicide item score, with
45% of patients showing a reduction in score. Only 6 patients
(3%) had slight worsening of suicide scores. No patients
attempted suicide or discontinued light therapy because of
emergent suicidality.

Conclusion: Light therapy relieves suicidal
ideation in patients with SAD consistent with overall clinical
improvement. Emergence of suicidal ideas or behaviors is very
uncommon with light therapy.