|Division of Mood Disorders, Department of Psychiatry, University
of B.C., 2255 Wesbrook Mall, Vancouver, Canada, V6T 2A1; 1Vancouver
Hospital and Health Sciences Centre, UBC Site; 2B.C. Women's
Hospital and Health Sciences Centre.
Objective: We report preliminary results from
a randomized, placebo-controlled study of dim versus bright light therapy in
patients with late luteal phase dysphoric disorder (LLPDD, equivalent to
premenstrual depression or dysphoric disorder).
Methods: In a PMS
Clinic, 14 female patients meeting DSM-III-R criteria for LLPDD (not
selected for seasonality) underwent a 6-cycle randomized, counter-balanced,
cross-over study. Each subject completed 2 cycles of prospective baseline
monitoring of mood and premenstrual symptoms, followed by 2 cycles of each
treatment. During the last 2 weeks of each treatment cycle, patients were
treated at home with a cool-white fluorescent light box, for 30 minutes
between 7 and 9 p.m. Patients were randomized to receive either 10,000 Lux
white light (active condition), or 500 Lux red light (placebo condition).
After 2 treatment cycles, patients were crossed over to the other condition
for another 2 cycles. Deception was used to obscure study objectives, and
pre-treatment expectation ratings were no different between conditions.
Patients were assessed each cycle at the end of the follicular and luteal
phases by blinded raters using standardized depression rating scales
(29-item Hamilton Depression Rating Scale (HAM-SAD), Beck Depression
Inventory (BDI), Clinical Global Impression (CGI), and the Self-rating Scale
for Premenstrual Tension Syndrome Scale (PMTS). Differences between luteal
phase and follicular phase scores within each cycle were summed across the 2
cycles. Non-parametric analyses (Friedman's 2-way ANOVA with planned
comparisons) were used to compare each treatment with baseline conditions.
improved under both active and placebo treatment conditions. However, the
bright white light condition significantly reduced depression scores
(29-item Ham-D, BDI, CGI) and PMS scores (PMTS) during the symptomatic
luteal phase compared to baseline (p<0.05), while the dim red light
condition did not. During the bright white light treatment, patients were
rated as much or very much improved on the CGI in 89% of the cycles,
compared to 65% of the cycles in the dim red light condition (p<0.03). There
were no significant effects of order of treatment. Side effects of the light
therapy were minimal. At study completion, 10 patients favoured the white
light overall, while 3 favoured the red light, and 1 had no preference.
results suggest that bright light therapy is an effective treatment for
premenstrual depression, compared to a placebo dim light condition. The
therapeutic effects of bright light were noted in both mood and physical
symptoms, and the side effects were minimal.
- Parry BL, Mahan AM, Mostofi N, et al: Light therapy of
late luteal phase dysphoric disorder: an extended study. Am J
Psychiatry 1993; 150:1417-1419
- Maskall DD, Lam RW, Carter D, et al: Seasonality of
symptoms in women with late luteal phase dysphoric disorder. Am J
Psychiatry, in press.
SLTBR Abstracts, Volume 9, 1997