Non-seasonal Depression Research Articles

Bright Light Therapy for Nonseasonal Depressive Disorders

Seasonal humor disorders are prone to have a link with daylight exposure. However, the effect of external light on nonseasonal disorders remains unclear. Evidence is lacking for the validity of bright light therapy (BLT) as an adjunctive treatment for these patients. To assess BLT effectiveness as an adjunctive treatment for nonseasonal depressive disorders. In March 2024, a comprehensive search was performed of publications in the MEDLINE, Embase, and Cochrane databases for randomized clinical trials (RCTs) evaluating BLT effects in patients with nonseasonal depression. RCTs published since 2000 were eligible. Comparisons between BLT and dim red light or antidepressant monotherapy alone were considered for inclusion. Using the systematic review approach on RCTs published from January 1, 2000, through March 25, 2024, differences between patients treated with and without BLT were estimated using the Mantel-Haenszel method; heterogeneity was assessed using I2 statistics. Remission of symptoms, response to treatment rates, and depression scales were assessed. In this systematic review and meta-analysis of 11 unique trials with data from 858 patients (649 female [75.6%]), statistically significant better remission and response rates were found in the BLT group (remission: 40.7% vs 23.5%; odds ratio [OR], 2.42; 95% CI, 1.50-3.91; P <.001; I2 = 21%; response: 60.4% vs 38.6%; OR, 2.34; 95% CI, 1.46-3.75; P <.001; I2 = 41%). With BLT, subgroup analysis based on follow-up times also showed better remission (<4 weeks: 27.4% vs 9.2%; OR, 3.59; 95% CI, 1.45-8.88; P = .005; I2 = 0% and >4 weeks: 46.6% vs 29.1%; OR, 2.18; 95% CI, 1.19-4.00; P = .01; I2 = 47%) and response (<4 weeks: 55.6% vs 27.4%; OR, 3.65; 95% CI, 1.81-7.33; P <.001; I2 = 35% and >4 weeks: 63.0% vs 44.9%; OR, 1.79; 95% CI, 1.01-3.17; P = .04; I2 = 32%) rates. Results of this systematic review and meta-analysis reveal that BLT was an effective adjunctive treatment for nonseasonal depressive disorders. Additionally, results suggest that BLT may improve the response time to the initial treatment.

Chinese self-report version of biological rhythms interview for assessment in neuropsychiatry (C-BRIAN-SR) - psychometric properties and prospective follow-up in patients with non-seasonal depression

ABSTRACT This study examined the psychometric properties and longitudinal changes of the self-reporting Traditional Chinese version of Biological Rhythms Interview for Assessment in Neuropsychiatry (C-BRIAN-SR) among healthy controls (HC) and patients with major depressive episode (MDE). Eighty patients with a current MDE and 80 HC were recruited. Assessments were repeated after two weeks in HC, and upon the discharge of MDE patients to examine the prospective changes upon remission of depression. The C-BRIAN-SR score was significantly higher in the MDE than HC group. The concurrent validity was supported by a positive correlation between scores of C-BRIAN-SR, Insomnia Severity Index and the Hospital Anxiety Depression Scale. C-BRIAN-SR negatively correlated MEQ in the MDE group (r = .30, p = 0.009), suggesting higher rhythm disturbances were associated with a tendency toward eveningness. A moderate test-retest reliability was found (r = .61, p < 0.001). A cut-off of 38.5 distinguished MDE subjects from HC with 82.9% of sensitivity and 81.0% of specificity. C-BRIAN-SR score normalized in remitted MDE patients but remained higher in the non-remitted. The C-BRIAN-SR is a valid and reliable scale for measuring the biological rhythms and may assist in the screening of patients with MDE.

Delivery of bright light therapy within the Veterans Health Administration

BackgroundBright light therapy (BLT) is efficacious for seasonal and non-seasonal depression. However, the current state of BLT use in practice is unknown, impeding efforts to identify and address utilization gaps. This study's objective was to investigate BLT delivery in a nationwide U.S. healthcare system. MethodsThis was a retrospective observational study of electronic medical records from all veterans who received outpatient mood disorder-related care in the Veterans Health Administration (VHA) from October 2008 through September 2020. BLT delivery was measured through the placement of light box consults. ResultsOf the 3,442,826 veterans who received outpatient mood disorder care, only 57,908 (1.68 %) received a light box consult. Consults increased by 548.44 % (99.9 % credible interval: 467.36 %, 638.74 %) over the timeframe and displayed a robust yearly cycle that peaked on either December 21st or December 22nd. Past mental health treatment for a mood disorder was associated with a higher probability of a consult (relative risk = 4.79, 99.9 % CI: 4.21, 5.60). There was low representation related to veteran age, gender, race, and ethnicity. LimitationsNo information on patients who declined light boxes or actual light box use following consult placement. ConclusionsOutpatient BLT delivery for mood disorders in the VHA remains low, despite significant growth over the past decade. It also displays a strong seasonal rhythm that peaks on the winter solstice, suggesting a limited focus on seasonal depression and a suboptimal reactive approach to changing sunlight. Overall, there exists ample opportunity for novel implementation efforts aimed at increasing utilization of BLT.

Mood correlates with circadian alignment in healthy individuals

ObjectiveTo determine whether there is a correlation between mood and the alignment between the timing of the circadian pacemaker (circadian phase) and the timing of sleep in healthy, euthymic individuals. MethodsParticipants were 25 first-year medical students (25.9 ± 3.3years, 16 females). Mood (Profile of Mood States, brief form) and circadian phase (salivary dim light melatonin onset) were assessed 4 times over 7weeks. Circadian alignment was determined using the dim light melatonin onset to average midsleep interval (phase angle difference). ResultsProfile of Mood States, brief form score and phase angle difference were correlated: later dim light melatonin onset relative to midsleep (shorter phase angle differences) was associated with worse mood (F1,75 =10.953, p = .001). There was no difference in Profile of Mood States, brief form score between female and male participants and no interaction between gender and phase angle difference. ConclusionsThere is a correlation between circadian alignment and mood among healthy individuals as has been found in individuals with seasonal and nonseasonal depression. This finding has implications for the development, prevention and treatment of mood disorders.

0623 Effects of bright light therapy on objective and subjective sleep in patients with non-seasonal depression and eveningness

Abstract Introduction This study reported the effect of bright light therapy with gradual advanced timing on the sleep parametersin patients with major depressive disorder (MDD) and eveningness. Methods A total of 93 adults were randomized to receive either 10,000 lux bright light therapy (BLT group) or 50lux dim red light therapy (placebo group) for a total of 5 weeks. Timings of both treatments were initiated at their habitual wake time and was advanced gradually each week. Sleep diary data were collected weekly. Actigraphic data were collected at the baseline and during the last week of the 5-week treatment. Sleep parameters including time in bed (TIB), sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST) and sleep efficiency (SE) were extracted. Concordance of the sleep diary and actigraphy sleep parameters were assessed by Pearson’s correlation with p-value adjusted for multiple comparisons. The changes of sleep parameters between the two groups were assessed by linear mixed model. Results Significant correlations between sleep diary and actigraphy were found for WASO (r=0.35, p = 0.01) and TST (r=0.40, p=0.01), but no correlation was found for TIB, SOL and SE. A greater advance in the diary-based light-out time (group*time p=0.03, 15 vs 32min) and rise time (group*time p=0.04, 38 vs 53min) was found in the BLT group compared to placebo group, while dairy-based WASO, TST and SE comparably improved with time in both groups. However, there were no significant difference between the two groups in all of the actigraphic parameters after treatment. Conclusion Five-week of either type of light therapy with gradual advance in timing improved subjective WASO, TST and SE, while BLT led to a greater advance in the light-out time and rise time when compared to the placebo group. These changes were not captured by the actigraphic measurements. The discrepancies between subjective and objective sleep parameters suggested the need to consider incorporating multiple measures when assessing sleep in patients with depression and eveningness. Support (if any) This project was supported by the Health and Medical Research Fund, The Government of Hong Kong SAR (Ref 12131131).

Adjunctive Bright Light Therapy for Non-Seasonal Major Depressive Disorder: A Randomized Controlled Trial.

This double-blind, randomized controlled trial assessed bright light therapy (BLT) augmentation efficacy compared with placebo light in treating non-seasonal major depressive disorder. The study participants belonged to a subtropical area (24.5°–25.5°N) with extensive daylight and included outpatients who had received stable dosages and various regimens of antidepressive agents for 4 weeks before enrollment. The outcomes were the 17-item Hamilton Depression Rating Scale, Montgomery–Asberg Depression Rating Scale, and Patient Health Questionnaire-9, which were assessed at weeks 1, 2, and 4. A total of 43 participants (mean age 45 years, ranging from 22–81) were randomized into the BLT [n = 22] and placebo light groups [n = 21]. After a 4-week administration of morning light therapy (30 min/day), depressive symptoms did not reduce significantly, which might be due to the small sample size. Nonetheless, this study had some strengths because it was conducted in warmer climates, unlike other studies, and examined diverse Asians with depression. Our findings suggest that several factors, such as poor drug response, different antidepressive regimens, duration of BLT, and daylength variability (i.e., natural daylight in the environment) may influence the utility of add-on BLT. Researchers may consider these important factors for future non-seasonal depression studies in subtropical environments.

Prediction of Dropout in a Randomized Controlled Trial of Adjunctive Light Treatment in Patients with Non-Seasonal Depression and Evening Chronotype.

The current study examined the possible predictors of dropout during a five-week light treatment (LT) with a gradual advance protocol in 93 patients with unipolar non-seasonal depression and evening chronotypes by comparing their clinical characteristics and performing a logistic regression analysis. Nineteen out of ninety-three (20%) subjects (80% female, 46.5 ± 11.7 years old) dropped out during the 5-week light treatment. Treatment non-adherence (i.e., receiving LT for less than 80% of the prescribed duration) over the first treatment week predicted a five-fold increase in risk of dropout during light therapy (OR: 5.85, CI: 1.41–24.21) after controlling for potential confounders, including age, gender, treatment group, rise time at the baseline, patient expectation, and treatment-emergent adverse events. There is a need to incorporate strategies to enhance treatment adherence and retention in both research and clinical settings. Chinese clinical trial registry (ChiCTR-IOR-15006937).

Blue-Light Therapy for Seasonal and Non-Seasonal Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

ObjectivesTo determine the efficacy and safety of blue-light therapy in seasonal and non-seasonal major depressive disorder (MDD), by comparison to active and inactive control conditions.MethodsWe searched Web of Science, EMBASE, Medline, PsycInfo, and Clinicaltrials.gov through January 17, 2022, for randomized controlled trials (RCTs) using search terms for blue/blue-enhanced, light therapy, and depression/seasonal affective disorder. Two independent reviewers extracted data. The primary outcome was the difference in endpoint scores on the Structured Interview Guide for the Hamilton Depression Rating Scale - Seasonal Affective Disorder (SIGH-SAD) or the Structured Interview Guide for the Hamilton Depression Rating Scale with Atypical Depression Supplement (SIGH-ADS) between blue light and comparison conditions. Secondary outcomes were response (≥ 50% improvement from baseline to endpoint on a depression scale) and remission rates (endpoint score in the remission range).ResultsOf 582 articles retrieved, we included nine RCTs (n = 347 participants) assessing blue-light therapy. Seven studies had participants with seasonal MDD and two studies included participants with non-seasonal MDD. Four studies compared blue light to an inactive light condition (efficacy studies), and five studies compared it to an active condition (comparison studies). For the primary outcome, a meta-analysis with random-effects models found no evidence for the efficacy of blue-light conditions compared to inactive conditions (mean difference [MD] = 2.43; 95% confidence interval [CI], −1.28 to 6.14, P = 0.20); however, blue-light also showed no differences compared to active conditions (MD = −0.11; 95% CI, −2.38 to 2.16, P = 0.93). There were no significant differences in response and remission rates between blue-light conditions and inactive or active light conditions. Blue-light therapy was overall well-tolerated.ConclusionsThe efficacy of blue-light therapy in the treatment of seasonal and non-seasonal MDD remains unproven. Future trials should be of longer duration, include larger sample sizes, and attempt to better standardize the parameters of light therapy.

Statement of Retraction: Bright light treatment of non-seasonal depression for 28 adolescents

Statement of Retraction: Bright light treatment of non-seasonal depression for 28 adolescents

737 Prediction of drop out in an adjunctive light treatment trial in patients with non-seasonal depression and evening chronotype

Abstract Introduction Drop out during treatment hampers therapeutic effect of interventions. The current study examines the possible predictors of drop out during the five-week light treatment in patients with unipolar non-seasonal depression and evening-chronotype. Methods Baseline characteristics including demographics, sleep diary parameters, light treatment prescribed, and early clinical outcomes changes were compared between the Drop out and Non drop out group. Logistic regression analysis was used to examine predictors for drop out. All data were analyzed in a modified intention to treat analysis with last observation carried forward approach. Results A total of 91 subjects (Female 79%, 46.3 ± 11.8 years old) were included in the analysis. There was no significant difference in the baseline demographic and clinical characteristics between the Drop out and Non drop out group. There was also no significant difference in the improvement of clinical parameters over the first week among the two groups. However, treatment non-adherence (in terms of compliance of less than 80% of prescribed duration) over the first treatment week predicts a five-fold increase in risk of drop out during light therapy. (OR: 5.85, CI: 1.414–24.205, p=0.015) after controlling for potential confounders including age, gender, treatment group, patient expectation, and treatment-emergent adverse events. Conclusion This study found that baseline clinical characteristics including depression severity and improvement of depressive symptoms in the initial week did not differ between the Drop out and Non drop out group. The drop out was also not affected by the type of light (dim red versus bright red light), indirectly supporting dim red light as a valid placebo in bright light therapy trial. Treatment adherence is the early phase of light treatment is an important predictor of drop out. Support (if any):

Temporal dynamics of subjective sleep profiles predicting mood improvements during adjunctive light therapy combined with sleep rescheduling

• Sleep-enhancement following light therapy may contribute to rapid mood improvements. • Subsequent alleviation of sleep-related daytime dysfunction may further improve mood. • Self-reported sleep variables may predict antidepressant response to light therapy. Light therapy yields inconsistent results in people with non-seasonal depression, which may in part be due to heterogeneous responses and the temporal dynamics of changes in sleep, daytime functioning and mood. This study assessed the timeline of the antidepressant effects of light therapy and sleep rescheduling relative to changes in sleep and daytime sleep-related factors, and sought to identify predictors of treatment response in young people with depression. Twenty-four individuals with depression (mean±SD: 21.2±1.0 years old;17% male) underwent adjunctive morning light therapy with a wake-up phase advance over four weeks. They completed the Beck Depression Inventory-II (BDI-II) and Leeds Sleep Evaluation Questionnaire. On average, BDI-II scores decreased significantly after four weeks of intervention ( F (2,32)=3.5, p =.044, ηp 2 =0.18). After two weeks, improvements in the ease of getting to sleep and sleep quality were significantly associated with BDI-II improvements ( F (2,21)=6.3, p =.007). From two to four weeks, improvements in daytime sleep-related factors were significantly associated with BDI-II improvements ( F (2,12)=6.0, p =.015). More sleep-related difficulties prior to the intervention tended to predict BDI-II improvements across the four weeks of light therapy ( F (2,14)=3.7, p =.053). Open-label design and small sample size. Sleep-enhancement emerging in the early phase of light therapy and sleep rescheduling may subsequently alleviate sleep-related daytime dysfunctions, which may in turn further improve mood. Controlled trials are required to confirm whether the antidepressant effects of light may be linked to the attenuation of sleep-related difficulties, and whether sleep difficulties may be useful predictors of the antidepressant response to light therapy.

Feasibility of Adjunctive Bright Light Therapy for Depressive Symptoms on an Acute Psychiatric Floor

Background: Bright light therapy (BLT) has been increasingly used as an experimental treatment in non-seasonal unipolar depression. While clinical trials have demonstrated the efficacy of BLT in ameliorating depression for outpatients, studies examining BLT in the psychiatric inpatient setting are currently lacking.Aim: The purpose of this study is to explore whether BLT as adjunctive treatment for depressive symptoms on an acute psychiatric floor is feasible and explore associated changes in depressive symptoms.Methods: An observational, cross-sectional study was conducted at State University of New York (SUNY) Upstate 4B acute inpatient psychiatric unit. BLT was administered to participating patients as adjunctive therapy to their psychopharmacological and psychotherapy treatments on a daily basis throughout their hospitalization. Beck Depression Inventory-II (BDI-II), Hamilton Rating Scale for Depression (HAM-D), and Outcome Questionnaire-45.2 (OQ-45.2) were administered before commencing BLT and after their last BLT session. Changes to the aforementioned measures before and after BLT treatment, the dose response of measure changes based on number of sessions, and the hospital length of stay along with the secondary factors such as age, gender, other psychiatric comorbidities, social factors, and psychiatric medications were analyzed.Results: BLT is feasible on acute psychiatric inpatient floor with adherence of 94% and has very few side effects. The repeated measures of depression and functioning demonstrated significant decrease in depression and improvement in functioning. Although not statistically significant, clinical meaningful dose-response relationship was found between a number of BLT sessions and improvement in depressive symptoms with five BLT sessions being an optimal amount for depression amelioration.Conclusion: BLT combined with the ongoing psychopharmacological treatment was well tolerated and easy to administer. It offers a simple, safe, and cost-effective approach to augmenting depressive treatment on an acute psychiatric floor.

Light therapy for seasonal affective disorder in visual impairment and blindness – a pilot study

Seasonal and non-seasonal depression are prevalent conditions in visual impairment (VI). We assessed the effects and side effects of light therapy in persons with severe VI/blindness who experienced recurrent depressive symptoms in winter corresponding to seasonal affective disorder (SAD) or subsyndromal SAD (sSAD). We included 18 persons (11 with severe VI, 3 with light perception and 4 with no light perception) who met screening criteria for sSAD/SAD in a single-arm, assessor-blinded trial of 6 weeks light therapy. In the 12 persons who completed the 6 weeks of treatment, the post-treatment depression score was reduced (p < 0.001), and subjective wellbeing (p = 0.01) and sleep quality were improved (p = 0.03). In 6/12 participants (50%), the post-treatment depression score was below the cut-off set for remission. In four participants with VI, side effects (glare or transiently altered visual function) led to dropout or exclusion. Light therapy was associated with a reduction in depressive symptoms in persons with severe VI/blindness. Eye safety remains a concern in persons with residual sight.

Adjunctive bright light treatment with gradual advance in unipolar major depressive disorder with evening chronotype - A randomized controlled trial.

Unipolar non-seasonal depressed patients with concomitant evening chronotype were associated with poor clinical outcomes and higher non-remission rate. This study aims to examine the efficacy of adjunctive bright light therapy with gradual timing advance in a randomized, assessor and prescriber-blinded controlled trial. Participants were randomly allocated to receive 5 weeks of either bright white light therapy (BLT) or dim red light (DRL) with the same advancement protocol. Participants were followed up till 5 months after treatment. Primary outcomes included (i) remission rate and (ii) the severity of depression. The analysis was conducted using Kaplan-Meier survival analysis, Cox proportional hazard analysis and linear mixed models. A total of 93 participants (46.4 ± 11.7 years old, 80% female) were randomized. The cumulative remission rate for the BLT and the DRL groups was 67.4% and 46.7%, respectively. Time to remission was shorter for the BLT group relative to the DRL group (log-rank test p = 0.024). Cox proportional hazard survival analysis showed that patients in the BLT group had a higher probability of achieving remission relative to patients in the DRL group [hazard ratio = 1.9 (95% CI = 1.1- 3.4), p = 0.026]. Further sensitivity analysis demonstrated greater improvement in 17-Hamilton Depression Score (group × time interaction, p = 0.04) in the BLT group for those who were adherent to light therapy. The use of bright light therapy with gradual advance protocol is an effective adjunctive treatment resulting in quicker and a higher rate of remission of depression in patients with non-seasonal unipolar depression and evening-chronotype.

Efficacy of light therapy for a college student sample with non-seasonal subthreshold depression: An RCT study

BackgroundLight therapy has been successfully used to treat seasonal and non-seasonal depression, but there is limited evidence for its efficacy in subthreshold depression. This study examines the efficacy of light therapy for symptoms of depression and anxiety in non-seasonal subthreshold depression. MethodsCollege students with non-seasonal subthreshold depression were recruited. The participants were randomly allocated to one of the three conditions: high- (LT-5000 lux) and low-intensity (LT-500 lux) light therapy conditions and a waiting-list control condition (WLC). The primary outcome was Hamilton Depression Rating Scale (HAMD), and secondary outcomes were Beck Depression Inventory-II (BDI-II) and state anxiety inventory (SAI), which were assessed at baseline (Week 0), during the trial (Week 4), and after completion of the light therapy (Week 8). ResultsA total of 142 participants completed the trial. The LT-5000 (effect size [d] = 1.56, 95% CI: 1.15 to 1.98) and LT-500 conditions (d = 0.84, 95% CI: 0.43 to 1.26) were significantly superior to the WLC condition. For the LT-5000, LT-500, and WLC conditions by the end of the 8-week trial, a response on the HAMD was achieved by 70.0%, 42.0% and 19.0% of the participants, and remission was achieved by 76.0%, 54.0%, and 19.0%, respectively. LimitationsThe subjects were not followed up regularly after completion of the trial. ConclusionLight therapy, both at high- and low-intensity, was efficacious in the treatment of college students with non-seasonal subthreshold depression. High-intensity light therapy was superior to low-intensity light therapy by the end of an 8-week trial.

Carbon monoxide: a critical physiological regulator sensitive to light

The mechanism by which humans absorb therapeutic light in winter seasonal and nonseasonal depression is unknown. Bright-light-induced release and generation of blood-borne gasotransmitters such as carbon monoxide (CO) may be one mechanism. Here, 24 healthy female volunteers had peripheral blood samples drawn. Samples were collected in a dimly lit room and protected from light exposure. Samples were analyzed for CO concentrations by gas chromatography after 2 h of continuous exposure to darkness vs. bright white light. In a similar confirmatory study, 11 additional volunteers had samples analyzed for CO concentrations after 2 h of continuous exposure to gentle rocking in darkness vs. in bright white light. In the first study, light-unexposed peripheral blood had a mean CO concentration of 1.8 ± 0.4 SD ppm/g. Identically treated samples with 2 h of rocking and exposure to bright white light at illuminance 10,000 lux had a mean CO of 3.6 ± 1.2 ppm/g (p < 0.0001). Post hoc analysis of that study showed that time of day was significantly inversely associated with increase in CO concentration under bright light vs. dark (p < 0.04). In a smaller confirmatory study of 11 healthy female volunteers, after 2 h of rocking, light-unexposed peripheral blood had a mean CO of 1.4 ± 0.5 SD ppm/g. Identically treated blood samples with 2 h of exposure to bright white light at illuminance 10,000 lux had a mean CO of 2.8 ± 1.7 ppm/g (p < 0.02). In conclusion, bright-light exposure robustly increases human blood CO in vitro. This supports the putative role of CO as a physiological regulator of circadian rhythms and light’s antidepressant effects. This human evidence replicates earlier data from a preclinical in vivo model. This effect may be stronger in the morning than in the afternoon.

Light Therapy for Patients With Bipolar Depression: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Bipolar disorder (BD) is challenging to treat, and fewer treatments are available for depressive episodes compared to mania. Light therapy is an evidence-based nonpharmacological treatment for seasonal and nonseasonal major depression, but fewer studies have examined its efficacy for patients with BD. Hence, we reviewed the evidence for adjunctive light therapy as a treatment for bipolar depression. We conducted a systematic review of databases from inception to June 30, 2019, for randomized, double-blind, placebo-controlled trials of light therapy in patients with BD (CRD42019128996). The primary outcome was change in clinician-rated depressive symptom score; secondary outcomes included clinical response, remission, acceptability, and treatment-emergent mood switches. We quantitatively pooled outcomes using meta-analysis with random-effects models. We identified seven trials representing 259 patients with BD. Light therapy was associated with a significant improvement in Hamilton Depression Rating Scale score (standardized mean difference = 0.43, 95% confidence interval [CI], 0.04 to 0.82, P = 0.03). There was also a significant difference in favor of light therapy for clinical response (odds ratio [OR] = 2.32; 95% CI, 1.12 to 4.81; P = 0.024) but not for remission. There was no difference in affective switches between active light and control conditions (OR = 1.30; 95% CI, 0.38 to 4.44; P = 0.67). Study limitations included different light treatment parameters, small sample sizes, short treatment durations, and variable quality across trials. There is positive but nonconclusive evidence that adjunctive light therapy reduces symptoms of bipolar depression and increases clinical response. Light therapy is well tolerated with no increased risk of affective switch.

Seasonal variation in specific depressive symptoms: A population based study

IntroductionDepression varies with season in Canadian youth. However, the symptom profile of seasonal depression may differ from that of non-seasonal depression. Here we evaluate which specific symptoms vary by season. MethodsUsing data from the 2015/2016 Canadian Community Health Survey, cross-sectional analysis was conducted. The Patient Health Questionnaire-9 (PHQ-9) was administered to respondents in 8 provinces/territories (n ≈ 53,000), with interviews conducted throughout the year. Seasonal effects were assessed using quadratic terms in a logistic regression model. Guided by previous literature and analysis, analyses were stratified by age into youth (age 12–24) and adult (age 25+) groups. ResultsIn the youth, 8 items of the PHQ-9 exhibited a significant season variation: lack of interest/pleasure, feeling depressed/down, hypersomnia/insomnia, lacking energy, poor appetite/overeating, feeling bad about yourself/ like a failure, being slow/fidgety, and trouble concentrating. In the adult group, only sleep and poor appetite/overeating exhibited a seasonal effect. Notably, symptoms of self-harm/suicide did not demonstrate seasonality in either group. LimitationsDue to use of cross-sectional data and a brief symptom rating scale, conventional criteria for Seasonal Affective Disorder or Major Depressive Disorder with seasonal variation could not be applied. Also, treatment status of respondents was not assessed in the survey, therefore possible confounding by this variable could not be assessed. ConclusionsA seasonal pattern was observed in most symptoms of depression in Canadian youth, whereas in adults, only symptoms related to sleep and appetite disturbance displayed seasonal variation.

Commercially Available Phototherapy Devices for Treatment of Depression: Physical Characteristics of Emitted Light.

Objective:The purpose of this study was to evaluate key physical properties of commercially available light devices for the treatment of seasonal or nonseasonal depression and to determine whether the devices met clinical criteria, derived from evidence‐based clinical guidelines, for generating adequate light at a reasonable distance, over a reasonable field of illumination, and with an adequate degree of user acceptability.Methods:Twelve manufacturers loaned or donated 24 light therapy devices: 16 light boxes, one light column, four light‐emitting diode beam devices, and three light visors. Each device was evaluated for spectral power distribution, light dispersion, subjective discomfort from glare, adequacy of diffusion, photopic illuminance (in lumens per square meter [lux]), melanopic illuminance relative to photopic illuminance (efficacy ratio), and blue light hazard relative to melanopic illuminance (protection ratio).Results:Physical properties of emitted light varied widely among devices. Only seven larger light boxes satisfied the three clinical criteria. Some devices advertised as “10,000‐lux” devices produced this intensity only at unreasonably close distances, over a restricted field, or with unacceptable glare or unevenness of illumination. Five other devices emitted light with physical properties whose efficacy is less supported by research, although these devices may be useful for some patients.Conclusions:These results should help clinicians identify appropriate devices for patients seeking light therapy for seasonal or nonseasonal depression. Device selection is key to ensuring that patients receive evidence‐supported doses of light.

20.4 BRIGHT LIGHT THERAPY FOR DEPRESSION IN ADOLESCENTS

Recent work has delineated a direct pathway from intrinsically photosensitive retinal ganglion cells to the perihabenular nucleus in the thalamus region, which is integrated with mood-regulating centers. Here, we review evidence supporting bright-light therapy (BLT) in adolescents with nonseasonal depression.