Light treatment for seasonal Winter depression in African-American vs Caucasian outpatients

Detecting Critical Decision Points during Cognitive-Behavioral Therapy and Light Therapy for Winter Depression Nonremission and Recurrence

Using data from a clinical trial comparing cognitive-behavioral therapy (CBT-SAD) and light therapy (LT) for winter seasonal affective disorder (SAD; N = 177), we explored critical decision points, or treatment weeks, that predict likelihood of nonremission at post-treatment and depression recurrence following treatment. In receiver operator characteristic (ROC) curve analyses, we used weekly Structured Clinical Interview for the Hamilton Rating Scale for Depression-SAD Version (SIGH-SAD) scores during treatment to predict nonremission at post-treatment (Week 6) and recurrence one winter later (Winter 1), two winters later (Winter 2), and any recurrence. Although several C-statistics of ≥ .70 were found, only Week 4 SIGH-SAD scores in CBT-SAD for nonremission had enough predictive ability to inform clinical decision-making (C-statistic = .80; sensitivity = .91; specificity = .68). Week 4 of CBT-SAD may be a critical time point to identify likely nonremitters who need tailoring of intervention, based on SIGH-SAD cutpoint score ≥ 13. This study illustrates how clinical trial data can inform detecting optimal decision points in treatment for identifying patients unlikely to remit, a critical first step to developing adaptive treatment strategies using decision rules to operationalize when and for whom treatment should change to maximize clinical benefit.

Seasonal pattern in bipolar disorders and cardio-vascular risk factors: A study from the FACE-BD cohort

Seasonal pattern (SP) and metabolic syndrome (MetS) are major contributors to poor outcome in bipolar disorders (BD). Patients with seasonal bipolar depression present increased appetite, carbohydrate cravings, weight gain, and hypersomnia, which can increase the development of MetS. MetS also appears to be associated with seasonal mood changes in the general population. This study examines whether a SP in BD is associated with an increased risk of MetS and its sub-components. One thousand four hundred and seventy-one outpatients with BD were systematically enrolled from 2009 to 2016. Inclusion required a disease duration of at least 5 years, with 486 (33%) patients with SP (SP+) and 985 (67%) without (SP-) according to the DSM IV-TR criteria. When using continuous measures of metabolic components, SP+ patients, as compared to SP-, suffered from higher levels for systolic blood pressure (p = 0.01), low-density lipoprotein cholesterol (p = 0.009), fasting glucose (p = 0.007), triglycerides levels (p = 0.03), a larger abdominal circumference (p = 0.02), and a higher body mass index (p = 0.07). In the covariance analysis, adjusted for gender, age, and bipolar subtype, as well as the number of depressive and hypomanic episode, SP+ patients had a significantly higher level of fasting glucose and higher systolic blood pressure. The frequency of MetS did not differ between groups (21.2% in SP- versus 23.9% in SP+). When using categorical definitions for abnormal metabolic components (International Diabetes Federation criteria), there were no differences between groups, except that SP+ patients were more overweight/obese as compared to SP- patients (55.03% versus 46.7%, respectively; p = 0.002) and tended to have more frequently high fasting glucose (18.2% versus 14.3%, respectively; p = 0.07). MetS was frequent in patients with BD, however not associated with SP. Patients with SP appeared more vulnerable to overweight/obesity and presented with higher levels of MetS subcomponents although these parameters were mainly in the normal range. All patients with BD should benefit from early screening and targeted management of cardio-vascular risk factors.

EGb761 attenuates depressive-like behaviours induced by long-term light deprivation in C57BL/6J mice through inhibition of NF-κB-IL-6 signalling pathway

Our previous investigation found that Ginkgo extract EGb761 could attenuate the depressive-like behaviours induced by a single injection of lipopolysaccharide in mice. However, it has not been investigated whether EGb761 is effective on depressive-like behaviours induced by long-term light deprivation and whether its effects are associated with the inhibition of NF-κB-IL-6 signalling pathway. In this study, three groups (vehicle group, EGb761 low-dose group, and EGb761 high-dose group) of C57BL/6J male mice were exposed to constant darkness for four weeks. The control mice remained on a 12 : 12 light-dark cycle. Depressive-like behaviours were evaluated by tail suspension test (TST), forced swim test (FST), and sucrose preference test (SPT). Spontaneous locomotor activity was evaluated by open field test (OFT). Levels of IL-6, IL-6 mRNA, NF-κB p65, phospho-NF-κB p65, IκBα, and phospho-IκBα were measured using Elisa, western blotting, or PCR assays. NF-κB p65 DNA binding activity was evaluated using Chemi Transcription Factor Assay Kit. Results showed long-term light deprivation prolonged the immobile time in TST and FST, shortened the latency to immobility in FST, reduced spontaneous locomotor activity in OFT, decreased sucrose preference in SPT, and increased levels of IL-6, IL-6 mRNA, NF-κB p65, phospho-NF-κB p65, and phospho-IκBα in hippocampal tissue. EGb761 dose-dependently reversed the changes of the above parameters induced by long-term light deprivation, without affecting spontaneous locomotor activity. We conclude that EGb761 could attenuate the depressive-like behaviours and inhibit the NF-κB-IL-6 signalling pathway in a light-deprivation-induced mouse model of depression.

Natural sleep and its seasonal variations in three pre-industrial societies

How did humans sleep before the modern era? Because the tools to measure sleep under natural conditions were developed long after the invention of the electric devices suspected of delaying and reducing sleep, we investigated sleep in three preindustrial societies [1-3]. We find that all three show similar sleep organization, suggesting that they express core human sleep patterns, most likely characteristic of pre-modern era Homo sapiens. Sleep periods, the times from onset to offset, averaged 6.9-8.5 hr, with sleep durations of 5.7-7.1 hr, amounts near the low end of those industrial societies [4-7]. There was a difference of nearly 1 hr between summer and winter sleep. Daily variation in sleep duration was strongly linked to time of onset, rather than offset. None of these groups began sleep near sunset, onset occurring, on average, 3.3 hr after sunset. Awakening was usually before sunrise. The sleep period consistently occurred during the nighttime period of falling environmental temperature, was not interrupted by extended periods of waking, and terminated, with vasoconstriction, near the nadir of daily ambient temperature. The daily cycle of temperature change, largely eliminated from modern sleep environments, may be a potent natural regulator of sleep. Light exposure was maximal in the morning and greatly decreased at noon, indicating that all three groups seek shade at midday and that light activation of the suprachiasmatic nucleus is maximal in the morning. Napping occurred on <7% of days in winter and <22% of days in summer. Mimicking aspects of the natural environment might be effective in treating certain modern sleep disorders.