Conclusion
- BLT is an effective adjunctive treatment for bipolar depression.
- Higher light intensity and longer duration of BLT may result in greater antidepressant effects, although the optimum duration and intensity are unknown.
- A significant limitation of this study was that the studies reviewed had high heterogeneity, and only a few were RCTs.
6. Takeshima M, Utsumi T, Aoki Y, et al. Efficacy and safety of bright light therapy for manic and depressive symptoms in patients with bipolar disorder: a systematic review and meta-analysis. Psychiatry Clin Neurosci. 2020;74(4):247-256.
Takeshima et al17 conducted a systematic review and meta-analysis to evaluate the efficacy and safety of BLT for manic and depressive symptoms in patients with bipolar disorder. They also evaluated if BLT could prevent recurrent mood episodes in patients with bipolar disorder.
Study design
- Researchers searched for studies of BLT for bipolar disorder in MEDLINE, CENTRAL, Embase, PsychInfo, and Clincialtrials.gov using the terms “bipolar disorder,” “phototherapy,” and “randomized controlled trial.”
- Two groups of 2 authors independently screened titles and abstracts for the following inclusion criteria: RCTs, 80% of patients diagnosed clinically with bipolar disorder, any type of light therapy, and control groups that included sham treatment or no light. Three groups of 2 authors then evaluated the quality of the studies and risk of bias.
- Six studies with a total of 280 participants were included.
- Primary outcome measures included rates of remission from depressive or manic episodes, rates of relapse from euthymic states, and changes in score on depression or mania rating scales.
Outcomes
- No significant differences were found between BLT and placebo for rates of remission from depressive episodes (P = .42), rates of manic switching (P = .26), or depressive symptom scores (P = .30).
- Sensitivity analysis for 3 studies with low overall indirectness revealed that BLT did have a significant antidepressant effect (P = .006).
- The most commonly reported adverse effects of BLT were headache (4.7%) and sleep disturbance (1.4%).
Conclusion
- This meta-analysis suggests that BLT does not have a significant antidepressant effect. However, a sensitivity analysis of studies with low overall indirectness showed that BLT does have a significant antidepressant effect.
- This review was based on a small number of RCTs that had inconsistent placebos (dim light, negative ion, no light, etc.) and varying parameters of BLT (light intensity, exposure duration, color of light), which may have contributed to the inconsistent results.