Light therapy in insomnia disorder: A systematic review and meta-analysis.

In the management of insomnia, physicians and patients are seeking alternative therapeutics to sleeping pills, in addition to sleep hygiene and cognitive behavioural therapy. Bright light therapy (LT) has proven its efficacy in circadian and mood disorders. We conducted a systematic literature review and meta-analysis according to Cochrane and PRISMA guidelines and using the databases Medline, Cochrane, and Web of Science, with a special focus on light therapy and insomnia. Twenty-two studies with a total of 685 participants were included, five of which with a high level of proof. Meta-analysis was performed with 13 of them: light therapy for insomnia compared with control conditions significantly improved wake after sleep onset (WASO: SMD = -0.61 [-1.11, -0.11]; p = 0.017; weighted difference of 11.2 min ±11.5 based on actigraphy, and SMD = -1.09 [-1.43, -0.74] (p < 0.001) weighted difference of -36.4 min ±15.05) based on sleep diary, but no other sleep measures such as sleep latency, total sleep time (TST), or sleep efficiency. Qualitative analysis of the review showed some improvement mainly in subjective measures. Morning light exposure advanced sleep-wake rhythms and evening exposure led to a delay. No worsening was observed in objective nor subjective measures, except for TST in one study with evening exposure. A light dose-response may exist but the studies' heterogeneity and publication bias limit the interpretation. To conclude, light therapy shows some effectiveness for sleep maintenance in insomnia disorders, but further research is needed to refine the light parameters to be chosen according to the type of insomnia, in the hope of developing personalised therapeutics.

Validity and Usage of the Seasonal Pattern Assessment Questionnaire (SPAQ) in a French Population of Patients with Depression, Bipolar Disorders and Controls.

The Seasonal Pattern Assessment Questionnaire (SPAQ), by Rosenthal et al. (1984), is by far the most used questionnaire to evaluate seasonal effects on mood and behavior. It includes a general seasonality score (GSS), composed of 6 items, from which cutoffs have been established to screen for seasonal affective disorder (SAD). However, it has never been validated in French and associations with circadian rhythm and symptoms of depression and bipolarity remain unclear. In this study, including 165 subjects (95 controls and 70 patients with depression or bipolar disorder), we confirmed the validity of the French version of the SPAQ, with a two-factor structure (a psychological factor: energy, mood, social activity and sleep length; and a food factor: weight and appetite) and a good fit was observed by all indicators. Mood and social activity dimensions were significantly affected by seasons in the depressed/bipolar group and a stronger global seasonality score (GSS) was associated with more severe phenotypes of depression and mania. Subjects meeting SAD and subsyndromal-SAD criteria also showed a delayed circadian rhythm compared to controls. Simple tools, such as the SPAQ, can aid the identification of significant seasonal changes and have direct implications on therapeutics including the use of bright light therapy in order to enhance personalized treatments, but also to prevent adverse seasonal effects.

Efficacy of light therapy versus antidepressant drugs, and of the combination versus monotherapy, in major depressive episodes: A systematic review and meta-analysis.

Although light therapy (LT) has been shown to be efficient in the treatment of seasonal and non-seasonal depression, it is underused in clinical settings and antidepressant drugs (AD) remain so far the usual first line treatment. The aim of this systematic review and weighted random effect meta-analysis is to examine the randomized controlled trials that compared directly light therapy and antidepressant drugs, as well as their combination (LT + AD). A total of 397 participants were included, with a moderate to severe major depressive episode, from seven independent populations. The median duration of intervention was 5 wks (range 2-8 wks). The superiority (lower depression score) of LT + Placebo compared to AD + Placebo was non-significant (SMD = 0.19 [-0.08-0.45]; p = 0.17). The combination LT + AD was superior to AD + Placebo (SMD = 0.56 [0.24-0.88]; p < 0.001). This superiority was confirmed in the subgroup of patients with non-seasonal depression (SMD = 0.55 [0.16-0.93]; p = 0.005). Meta-analyses showed no or small heterogeneity between studies (I2 = 0%, 18.41%, and 39.23% respectively). No potential publication biases were observed by statistical tests and visual inspection of the funnel plots. No differences were observed between LT and AD, with a clear superiority of the combination, thus both LT monotherapy and combination may be proposed as a first line treatment in seasonal and non-seasonal depression.