Psychiatry Journal Club Bright light therapy for bipolar depression: A review of 6 studies Sy Atezaz Saeed, MD, MS, and Radhika J. Kothadia, MD epressive episodes are part of Research to investigate novel therapeu- DSM-5 criteria for bipolar II dis- tics for bipolar depression is a high priority. order, and are also often experi- Patients with bipolar disorder are suscep- D 1 enced by patients with bipolar I disorder. tible to environmental cues that alter circa- Depressive episodes predominate the clini- dian rhythms and trigger relapse. Recent cal course of bipolar disorder.2,3 Compared studies have suggested that bright light with manic and hypomanic episodes, bipo- therapy (BLT), an accepted treatment for Sy Atezaz Saeed, MD, MS lar depressive episodes have a stronger seasonal depression, also may be useful for Department Editor association with long-term morbidity, sui- treating nonseasonal depression.10 Patients cidal behavior, and impaired functioning.4,5 with bipolar depression frequently have Approximately 20% to 60% of patients with delayed sleep phase and atypical depres- Recent evidence bipolar disorder attempt suicide at least sive features (hypersomnia, hyperpha- once in their lifetime, and 4% to 19% gia, and lethargy), which predict response suggests BLT die by suicide. Compared with the general to light therapy.11 In this article, we review may help reduce population, the risk of death by suicide is 6 recent studies that evaluated the effi- depressive symptoms 10 to 30 times higher in patients with bipo- cacy and safety of BLT for treating bipolar lar disorder.6 depression (Table,12-17 page 41). Treatment of bipolar depression is less investigated than treatment of unipolar 1. Wang S, Zhang Z, Yao L, et al. Bright light depression or bipolar mania. The mainstays therapy in treatment of patients with bipolar of treatment for bipolar depression include disorder: a systematic review and meta-anal- mood stabilizers (eg, lithium, valproic ysis. PLoS ONE. 2020;15(5):e0232798. doi: acid, or lamotrigine), second-generation 10.1371/journal.pone.0232798 antipsychotics (eg, risperidone, quetiap- ine, lurasidone, or olanzapine), adjunctive In this meta-analysis, Wang et al12 examined antidepressants (eg, selective serotonin the role of BLT in treating bipolar depres- reuptake inhibitors or bupropion), and sion. They also explored variables of BLT, combinations of the above. While signifi- including duration, timing, color, and color cant progress has been made in the treat- ment of mania, achieving remission for Dr. Saeed is Professor and Chair, Department of Psychiatry and Discuss this article at patients with bipolar depression remains a Behavioral Medicine, East Carolina University Brody School www.facebook.com/ challenge. Anti-manic medications reduce of Medicine, Greenville, North Carolina. Dr. Saeed is CURRENT MDedgePsychiatry PSYCHIATRY’s Department Editor, Psychiatry Journal Club. Dr. Kothadia depressive symptoms in only one-third of is a PGY-1 Psychiatry Resident, Prisma Health–Midlands, Columbia, patients.7 Antidepressant monotherapy South Carolina. can induce hypomania and rapid cycling.8 Disclosures The authors report no financial relationships with any companies Electroconvulsive therapy has also been whose products are mentioned in this article, or with manufacturers used for treatment-resistant bipolar depres- of competing products. Current Psychiatry 40 May 2021 sion, but is usually reserved as a last resort.9 doi: 10.12788/cp.0114 Psychiatry Journal Club Table Bright light therapy for bipolar depression: 6 studies Study Design Outcomes Wang et al12 Review and meta-analysis of 5 RCTs and Compared with placebo, BLT 7 cohort studies evaluating BLT for 847 significantly decreased depression patients with bipolar depression severity (P < .05) Lam et al13 Review and meta-analysis of 7 RCTs Compared with control conditions, BLT evaluating BLT for 259 patients with was associated with a small to moderate bipolar depression but statistically significant improvement in clinician-rated depressive symptoms (P = .03) Hirakawa et al14 Review and meta-analysis of 4 RCTs BLT had a significant effect on response evaluating BLT for 190 patients with rates (P = .002) but not on remission bipolar depression rates (P = .34) Clinical Point D’Agostino Review of 6 studies evaluating triple All studies reported improvement in et al15 chronotherapy (total sleep deprivation, HAM-D scores at the end of treatment, One meta-analysis sleep phase advance, and BLT) for 190 with response rates ranging from 50% patients with MDD or bipolar depression to 84% found that BLT at Dallaspezia Meta-analysis of 11 studies (including Analyses of all 11 studies and of just various durations, and Benedetti16 5 RCTs) evaluating BLT for depressive the 5 RCTs found BLT had a positive symptoms in 195 patients significant effect on depressive timings, colors, and symptoms (both P < .001) color temperatures Takeshima Review and meta-analysis of 6 studies No significant differences were found et al17 evaluating BLT for manic and depressive between BLT and placebo for rate of reduced depression symptoms in 280 patients with bipolar remission from depressive episodes, severity disorder rate of manic switching, or depressive symptom scores BLT: bright light therapy; HAM-D: Hamilton Depression Rating Scale; MDD: major depressive disorder; RCTs: randomized controlled trials temperature, and how these factors may for depressive symptoms, and efficacy of affect the severity of depressive symptoms. different light color/color temperatures for depressive symptoms. Study design • Two researchers conducted a system- Outcomes atic literature search on PubMed, Web of • As assessed by the Hamilton Depression Science, Embase, Cochrane Library, and Rating Scale (HAM-D); Inventory of Cumulative Index of Nursing and Allied Depressive Symptomatology, Clinician Health Literature (CINAHL), as well as 4 Rating; or the Structured Interview Guide for Chinese databases from inception to March the HAM-D, depression severity significantly 2020. Search terms included “phototherapy,” decreased (P < .05) with BLT intensity ≥5,000 “bright light therapy,” “bipolar disorder,” lux when compared with placebo. and “bipolar affective disorder.” • Subgroup analyses suggested that • Inclusion criteria called for random- BLT can improve depression severity with ized controlled trials (RCTs) or cohort or without adjuvant therapy. Duration of studies that used a clearly defined diagno- <10 hours and >10 hours with morning sis of bipolar depression. Five RCTs and 7 light vs morning plus evening light ther- cohort studies with a total of 847 partici- apy all produced a significant decrease in pants were included. depressive symptoms (P < .05). • The primary outcomes were depression • White light therapy also significantly Current Psychiatry severity, efficacy of duration/timing of BLT decreased depression severity (P < .05). Vol. 20, No. 5 41 continued Psychiatry Journal Club Color temperatures >4,500K and <4,500K Data for remission obtained from 5 trials both significantly decreased depression showed no significant difference between severity (P < .05). BLT and control (P = .09). • Compared with control, BLT was not Conclusion associated with an increased risk of affec- • BLT (at various durations, timings, tive switches (P= .67). colors, and color temperatures) can reduce depression severity. Conclusion • This analysis only included studies • This study suggests a small to moder- that showed short-term improvements in ate but significant effect of BLT in reducing depressive symptoms, which brings into depressive symptoms. question the long-term utility of BLT. • Study limitations included inconsis- tent light parameters, short follow-up time, Clinical Point 2. Lam RW, Teng MY, Jung YE, et al. Light small sample sizes, and the possibility that A review of 7 RCTs therapy for patients with bipolar depression: control conditions had treatment effects (eg, systematic review and meta-analysis of ran- dim light as control vs no light). found a small to domized controlled trials. Can J Psychiatry. moderate but 2020;65(5):290-300. 3. Hirakawa H, Terao T, Muronaga M, et al. significant effect Adjunctive bright light therapy for treating of BLT in reducing Lam et al13 examined the role of BLT for bipolar depression: a systematic review and patients with bipolar depression in a sys- meta-analysis of randomized controlled tri- depressive tematic review and meta-analysis. als. Brain Behav. 2020;10(12):ee01876. doi. symptoms org/10.1002/brb3.1876 Study design • Investigators conducted a systematic Hirakawa et al14 assessed the role of adjunc- review of RCTs of BLT for patients with tive BLT for treating bipolar depression. bipolar depression. Articles were obtained Previous meta-analyses focused on case- from Web of Science, Embase, MEDLINE, control studies that assessed the effects PsycInfo, and Clinicaltrials.gov using the of BLT and sleep deprivation therapy on search terms “light therapy,” “photother- depressive symptoms, but this meta-analy- apy,” “light treatment,” and “bipolar.” sis reviewed RCTs that did not include • Inclusion criteria required patients sleep deprivation therapy. diagnosed with bipolar disorder cur- rently experiencing a depressive episode, Study design a clinician-rated measure of depressive • Two authors searched Embase, symptomatology, a specific light interven- MEDLINE, Scopus, Cochrane Central tion, and a randomized trial design with a Register of Controlled Trials (CENTRAL),