Prospectively assessed summer mood status in major depression, recurrent with seasonal pattern: Evidence for SAD's construct validity.

OBJECTIVE: Seasonal patterns are often undetectable in population-based depression studies, calling into question the existence of winter seasonal affective disorder (SAD). If SAD has construct validity, individuals with SAD should show spontaneous depression remission in the summer. Data are sparse on prospectively assessed summer mood status in confirmed SAD patients. METHOD: We conducted prospective summer followup of community adults who, the winter before, were diagnosed with Major Depression, Recurrent with Seasonal Pattern on the Structured Clinical Interview for DSM-IV Axis I Disorders, developed a current SAD episode on the Structured Interview Guide for the Hamilton Rating Scale for Depression-Seasonal Affective Disorder Version (SIGH-SAD), and enrolled in a clinical trial comparing group cognitive-behavioral therapy for SAD and light therapy. In July/August after treatment, 143/153 (93.5 %) participants provided data on the SIGH-SAD, the Beck Depression Inventory-Second Edition, and the Longitudinal Interval Followup Evaluation (LIFE). RESULTS: Summer mean depression scores were in the normal range, with the substantial majority in remission across different measures. On the LIFE, 113/143 (79.0 %) experienced complete summer remission, 19/143 (13.3 %) experienced partial summer remission, and 11/143 (7.7 %) had major depression in the summer. Depression scores were significantly lower at summer than post-treatment in both treatments, indicating incomplete treatment response. LIMITATIONS: This was a single-site study with a relatively homogeneous sample. CONCLUSIONS: Supporting construct validity for SAD, the substantial majority experienced complete summer remission, with a minority in partial remission and a very small minority in episode. Both treatments left residual symptoms at treatment endpoint compared to summer.

Mediating role of weight concerns in the relationship between seasonality and eating behavior among community-dwelling older adults: A path analysis.

BACKGROUND: Weight concerns are common among older adults, and it is unclear how they may impact the relationship between seasonality and eating behaviors, which can contribute to various health-related issues. AIM: This study investigated the mediating role of weight concerns in the relationship between seasonality and eating behavior among community-dwelling older adults. METHOD: A descriptive correlational analytical design was used on 200 randomly chosen participants who completed the Personal Inventory for Depression and Seasonal Affective Disorder Self-Assessment Version, the Adult Eating Behavior Questionnaire, and the Weight Concern Subscale. A path analysis was conducted to test the hypothesized model. RESULTS: The study findings indicated that most older adults reported moderate-to-severe seasonal variations, moderate enjoyment of food, emotional overeating, emotional undereating, and food fussiness. Weight concern partially mediated the relationship between seasonality and eating behavior. CONCLUSION: By understanding the complex interplay between these factors, weight concerns may play an essential role in mediating the effects of seasonal changes on eating behavior, while seasonal winter symptoms may directly impact eating behavior. These results have potential implications for nurses' efforts to develop interventions to promote healthy eating behaviors and manage weight concerns during seasonal variations, especially in the winter.

Change in Seasonal Beliefs Mediates the Durability Advantage of Cognitive-Behavioral Therapy Over Light Therapy for Winter Depression.

In treating an acute episode of winter depression, cognitive-behavioral therapy for seasonal affective disorder (CBT-SAD) and light therapy are comparably efficacious, with improvement in depression symptoms during CBT-SAD mediated by reduced seasonal beliefs (i.e., maladaptive thoughts about the seasons, light availability, and weather). Here, we tested whether the enduring benefit of CBT-SAD over light therapy following treatment is associated with offsetting seasonal beliefs during CBT-SAD. Currently depressed adults with Major Depression, Recurrent with Seasonal Pattern (N = 177) were randomized to 6 weeks of light therapy or group CBT-SAD and followedup one and two winters after treatment. Outcomes measured during treatment and at each follow-up included depression symptoms on the Structured Clinical Interview for the Hamilton Rating Scale for Depression-SAD Version and Beck Depression Inventory-Second Edition. Candidate mediators measured at pre-, mid-, and posttreatment were SAD-specific negative cognitions (Seasonal Beliefs Questionnaire; SBQ); general depressogenic cognitions (Dysfunctional Attitudes Scale; DAS); brooding rumination (Ruminative Response Scale-Brooding subscale; RRS-B); and chronotype (Morningness-Eveningness Questionnaire; MEQ). Latent growth curve mediation models found a significant positive path from treatment group to the slope of SBQ during treatment, with CBT-SAD showing larger improvements in seasonal beliefs with overall change in seasonal beliefs in the medium-effect range, and significant positive paths from SBQ slope to depression scores at the first and second winter follow-ups, indicating greater change towards more flexible seasonal beliefs during active treatment was associated with less severe depression symptoms following treatment. Estimated indirect effects (treatment group → SBQ change * SBQ change → outcome) were also significant at each follow-up for each outcome with ßindirect ranging from .091 to .162. Models also found significant positive paths from treatment group to the slope of MEQ and RRS-B during treatment, with light therapy showing a greater increase in "morningness" and CBT-SAD showing a greater decrease in brooding during active treatment; however, neither construct emerged as a mediator of follow-up depression scores. Change in seasonal beliefs during treatment mediates both the acute antidepressant and long-term effects of CBT-SAD and explains lower depression severity following CBT-SAD relative to light therapy.

Elusive hypersomnolence in seasonal affective disorder: actigraphic and self-reported sleep in and out of depressive episodes.

BACKGROUND: Hypersomnolence has been considered a prominent feature of seasonal affective disorder (SAD) despite mixed research findings. In the largest multi-season study conducted to date, we aimed to clarify the nature and extent of hypersomnolence in SAD using multiple measurements during winter depressive episodes and summer remission. METHODS: Sleep measurements assessed in individuals with SAD and nonseasonal, never-depressed controls included actigraphy, daily sleep diaries, retrospective self-report questionnaires, and self-reported hypersomnia assessed via clinical interviews. To characterize hypersomnolence in SAD we (1) compared sleep between diagnostic groups and seasons, (2) examined correlates of self-reported hypersomnia in SAD, and (3) assessed agreement between commonly used measurement modalities. RESULTS: In winter compared to summer, individuals with SAD (n = 64) reported sleeping 72 min longer based on clinical interviews (p < 0.001) and 23 min longer based on actigraphy (p = 0.011). Controls (n = 80) did not differ across seasons. There were no seasonal or group differences on total sleep time when assessed by sleep diaries or retrospective self-reports (p's > 0.05). Endorsement of winter hypersomnia in SAD participants was predicted by greater fatigue, total sleep time, time in bed, naps, and later sleep midpoints (p's < 0.05). CONCLUSION: Despite a winter increase in total sleep time and year-round elevated daytime sleepiness, the average total sleep time (7 h) suggest hypersomnolence is a poor characterization of SAD. Importantly, self-reported hypersomnia captures multiple sleep disruptions, not solely lengthened sleep duration. We recommend using a multimodal assessment of hypersomnolence in mood disorders prior to sleep intervention.

Physical Activity, Seasonal Sensitivity and Psychological Well-Being of People of Different Age Groups Living in Extreme Environments.

Physical activity can prevent many organic and mental pathologies. For people living in extreme southern high-latitude environments, weather conditions can affect these activities, altering their psychological well-being and favoring the prevalence of seasonal sensitivity (SS). This study aims to determine the relationships between the practice of physical activity, seasonal sensitivity and well-being in people living in high southern latitudes. A cross-sectional study was conducted, using the Seasonal Pattern Assessment Questionnaire (SPAQ), applying a psychological well-being scale, and determining sports practice according to the recommendations of the World Health Organization (WHO) for the 370 male (n = 209; 55%) and female (n = 173; 45%) participants. The main results indicated that 194 people (52 ± 7.7 years) reported physical activity. High-intensity physical activity practitioners recorded a significantly lower proportion of SS. In terms of psychological well-being, an adverse effect was found between the Seasonal Score Index (SSI) and five subcategories of the Ryff well-being scale. In conclusion, those who perform high-intensity physical activity have a lower SS, and those who have a higher SS have a lower psychological well-being.

Elucidating treatment targets and mediators within a confirmatory efficacy trial: study protocol for a randomized controlled trial of cognitive-behavioral therapy vs. light therapy for winter depression.

BACKGROUND: This study is a confirmatory efficacy trial of two treatments for winter seasonal affective disorder (SAD): SAD-tailored group cognitive-behavioral therapy (CBT-SAD) and light therapy (LT). In our previous efficacy trial, post-treatment outcomes for CBT-SAD and LT were very similar, but CBT-SAD was associated with fewer depression recurrences two winters later than LT (27.3% in CBT-SAD vs. 45.6% in LT). CBT-SAD engaged and altered a specific mechanism of action, seasonal beliefs, which mediated CBT-SAD's acute antidepressant effects and CBT-SAD's enduring benefit over LT. Seasonal beliefs are theoretically distinct from LT's assumed target and mechanism: correction of circadian phase. This study applies the experimental therapeutics approach to determine how each treatment works when it is effective and to identify the best candidates for each. Biomarkers of LT's target and effect include circadian phase angle difference and the post-illumination pupil response. Biomarkers of CBT-SAD's target and effect include decreased pupillary and sustained frontal gamma-band EEG responses to seasonal words, which are hypothesized as biomarkers of seasonal beliefs, reflecting less engagement with seasonal stimuli following CBT-SAD. In addition to determining change mechanisms, this study tests the efficacy of a "switch" decision rule upon recurrence to inform clinical decision-making in practice. METHODS: Adults with SAD (target N = 160) will be randomzied to 6-weeks of CBT-SAD or LT in winter 1; followed in winter 2; and, if a depression recurrence occurs, offered cross-over into the alternate treatment (i.e., switch from LT➔CBT-SAD or CBT-SAD➔LT). All subjects will be followed in winter 3. Biomarker assessments occur at pre-, mid-, and post-treatment in winter 1, at winter 2 follow-up (and again at mid-/post-treatment for those crossed-over), and at winter 3 follow-up. Primary efficacy analyses will test superiority of CBT-SAD over LT on depression recurrence status (the primary outcome). Mediation analyses will use parallel process latent growth curve modeling. DISCUSSION: Consistent with the National Institute of Mental Health's priorities for demonstrating target engagement at the level of Research Domain Criteria-relevant biomarkers, this work aims to confirm the targets and mechanisms of LT and CBT-SAD to maximize the impact of future dissemination efforts. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03691792 . Registered on October 2, 2018.

Effect of Hometown Seasonality on Undergraduate Students' Risk of Developing Seasonal Affective Disorder.

Seasonal affective disorder (SAD) is a prevalent and potentially serious medical condition. Young adults are at particularly high risk. However, it is unknown if college students whose hometowns are in geographic areas with less seasonal variability, such as in the state of Hawai'i, are particularly vulnerable if they attend schools in areas with seasonal variability. An adapted version of the Seasonal Patterns Assessment Questionnaire (SPAQ) was administered to students at 3 universities to test this hypothesis. Surveys were administered twice: a baseline (T0) assessment in the fall and a follow-up (T1) assessment in the winter and were administered in the second month of each semester. A linear regression model was constructed to identify potential risk factors for developing seasonal fluctuations in mood (SPAQ scores T1-T0). Study subjects (n=115) from non-seasonal hometowns had a 1.6-point greater increase in SPAQ score than students from seasonal hometowns (-0.26 ± 3.88 vs 1.35 ± 3.03; P =.01). This difference is independent of demographic and lifestyle predictors (linear regression coefficient: ß = 1.73; standard error = 0.68; P =.012). Interestingly, SPAQ score changes of students from seasonal hometowns did not differ significantly from 0 (t = -0.97; P =.33), indicating that they did not generally experience seasonal shifts in depressive symptoms. Students from less seasonal hometowns and counselors at seasonal institutions should be aware that these students could be more at risk of developing depressive symptoms and address these concerns before interfering with students' daily and academic lives.

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

OBJECTIVE: 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). RESULTS: 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. CONCLUSION: 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.

Light therapy in non-seasonal depression: An update meta-analysis.

The effect of light therapy in treating seasonal affective disorder has been demonstrated amongst previous studies. However, the effect of light therapy in treating non-seasonal depression remains unclear. This meta-analysis aimed to determine the efficacy of light therapy in non-seasonal depression. We searched for randomized controlled trials (RCTs) in the PubMed, Web of Science, Chinese National Knowledge Infrastructure, and Chinese Biomedical Database up to February 2020. The pooled post-trial standardized mean difference in depression scores with corresponding 95% confidence intervals was calculated to evaluate the efficacy of light therapy in non-seasonal depression. A total of 23 RCTs with 1120 participants were included. The meta-analysis demonstrated the light therapy was significantly more effective than comparative treatments. Subgroup analyses revealed that none of the factors explained the significantly heterogeneity. Light therapy has a statistically significant mild to moderate treatment effect in reducing depressive symptoms, can be used as a clinical therapy in treating non-seasonal depression. But the quality of evidence is still low, more well-designed studies with larger sample size and high quality are needed to confirm the efficiency of light therapy in treating non-seasonal depression.

Seasonal variation in specific depressive symptoms: A population based study.

INTRODUCTION: Depression 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. METHODS: Using 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. RESULTS: In 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. LIMITATIONS: Due 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. CONCLUSIONS: A 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.

Seasonality and symptoms of depression: A systematic review of the literature.

AIMS: Lay opinions and published papers alike suggest mood varies with the seasons, commonly framed as higher rates of depression mood in winter. Memory and confirmation bias may have influenced previous studies. We therefore systematically searched for and reviewed studies on the topic, but excluded study designs where explicit referrals to seasonality were included in questions, interviews or data collection. METHODS: Systematic literature search in Cochrane database, DARE, Medline, Embase, PsychINFO and CINAHL, reporting according to the PRISMA framework, and study quality assessment using the Newcastle-Ottawa scale. Two authors independently assessed each study for inclusion and quality assessment. Due to large heterogeneity, we used a descriptive review of the studies. RESULTS: Among the 41 included studies, there was great heterogeneity in regards to included symptoms and disorder definitions, operationalisation and measurement. We also observed important heterogeneity in how definitions of 'seasons' as well as study design, reporting and quality. This heterogeneity precluded meta-analysis and publication bias analysis. Thirteen of the studies suggested more depression in winter. The remaining studies suggested no seasonal pattern, seasonality outside winter, or inconclusive results. CONCLUSIONS: The results of this review suggest that the research field of seasonal variations in mood disorders is fragmented, and important questions remain unanswered. There is some support for seasonal variation in clinical depression, but our results contest a general population shift towards lower mood and more sub-threshold symptoms at regular intervals throughout the year. We suggest future research on this issue should be aware of potential bias by design and take into account other biological and behavioural seasonal changes that may nullify or exacerbate any impact on mood.

A measure of cognitions specific to seasonal depression: Development and validation of the Seasonal Beliefs Questionnaire.

We introduce the Seasonal Beliefs Questionnaire (SBQ), a self-report inventory of maladaptive thoughts about the seasons, light availability, and weather conditions, proposed to constitute a unique cognitive vulnerability to winter seasonal affective disorder (SAD; Rohan, Roecklein, & Haaga, 2009). Potential items were derived from a qualitative analysis of self-reported thoughts during SAD-tailored cognitive-behavioral therapy (CBT-SAD) and subsequently refined based on qualitative feedback from 48 SAD patients. In the psychometric study (N = 536 college students), exploratory and confirmatory factor analyses pruned the items to a 26-item scale with a 5-factor solution, demonstrating good internal consistency, convergent and divergent validity, and 2-week test-retest reliability. In a known groups comparison, the SBQ discriminated SAD patients (n = 86) from both nonseasonal major depressive disorder (MDD) patients (n = 30) and healthy controls (n = 110), whereas a generic measure of depressogenic cognitive vulnerability (the Dysfunctional Attitudes Scale [DAS]) discriminated MDD patients from the other groups. In a randomized clinical trial comparing CBT-SAD with light therapy (N = 177), SBQ scores improved at twice the rate in CBT-SAD than in light therapy. Greater change in SBQ scores during CBT-SAD, but not during light therapy, was associated with a lower risk of depression recurrence 2 winters later. In contrast, DAS scores improved comparably during CBT-SAD and light therapy, and DAS change was unrelated to recurrence following either treatment. These results support using the SBQ as a brief assessment tool for a SAD-specific cognitive vulnerability and as a treatment target in CBT-SAD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Tanning dependence and seasonal affective disorder are frequent among sunbathers but are not associated.

Ultraviolet radiation (UVR) is a known risk factor for skin cancers. Those who are tanning dependent seek out UVR exposure. Many tanners have expressed symptoms of seasonal affective disorder (SAD), but conclusive evidence of a connection with tanning dependence is lacking. We evaluated the frequency of tanning dependence or abuse and symptoms of SAD among Finnish sunbathers and analysed whether phenomena are associated which could indicate a common biological mechanism. Sunbathing related tanning dependence/abuse among Finnish sunbathers were assessed using the Structured Interview for Tanning Abuse and Dependence measure (SITAD), and symptoms of SAD were assessed with the Seasonal Pattern Assessment Questionnaire (SPAQ). Of 229 sunbathers, 8% (n = 18) were classified as tanning-dependent, and 26% (n = 59) were classified as tanning abusers. Additionally, 16% (n = 37) met the criteria for SAD, and 26% (n = 60) met the criteria for subsyndromal seasonal affective disorder (S-SAD), but there was no significant association between tanning dependence or abuse and SAD or S-SAD. Sunbathing dependence or abuse and SAD/S-SAD were frequent among sunbathers, and they may promote sun-seeking risk behaviour. However, within this sample, tanning dependence and SAD/S-SAD were not associated.

Sensory processing sensitivity and its association with seasonal affective disorder.

It has been hypothesized that an increased sensitivity to the surroundings, can leave some individuals vulnerable to experience the environmental stress of winter more overwhelming, thus leading to a greater risk of Seasonal Affective Disorder (SAD). However, the association between trait Sensory Processing Sensitivity (SPS) and SAD is not known. We therefore aimed to investigate: 1)cross-seasonal group differences in trait SPS, in 31 individuals with SAD compared to 30 age-, gender- and education-matched healthy controls, and 2)the association between trait SPS in remitted phase (summer) and depression severity in symptomatic phase (winter) in individuals with SAD. All participants completed the Highly Sensitive Person Scale, as a measure of SPS, and the Major Depression Inventory in summer and in winter, using a longitudinal and seasonally counterbalanced design. In both remitted and symptomatic phase, individuals with SAD exhibited higher trait SPS compared to healthy controls, which for individuals with SAD was heightened during depression in winter. Notably, when averaged across season, about 25% of the individuals with SAD display high-sensitivity whereas this is only the case for 5% of the healthy controls. In addition, higher trait SPS in summer was associated with more severe SAD symptoms in winter. Our findings suggest that those with SAD are more likely to score high on SPS and that high SPS may be a vulnerability marker related to more severe SAD symptomatology.

Rest-activity rhythms characteristics and seasonal changes in seasonal affective disorder.

Identifying objectively measurable seasonal changes in 24-h activity patterns (rest-activity rhythms or RARs) that occur in seasonal affective disorder (SAD) could help guide research and practice towards new monitoring tools or prevention targets. We quantified RARs from actigraphy data using non-parametric and extended cosine based approaches, then compared RARs between people with SAD and healthy controls in the summer (n = 70) and winter seasons (n = 84). We also characterized the within-person seasonal RAR changes that occurred in the SAD (n = 19) and control (n = 26) participants who contributed repeated measures. Only controls had significant winter increases in RAR fragmentation (intra-daily variability; in controls mean winter-summer changes (log scale) = 0.05, 0.21 standard deviation, p = 0.03). In SAD participants only, estimated evening settling times (down-mesor) were an average of 30 min earlier in the winter compared with the summer (1-h standard deviation, p = 0.045). These RAR characteristics correlated with greater fatigue (Spearman r = 0.36) but not depression symptom severity. Additional research is needed to ascertain why healthy controls, but not people with SAD, appear to have increased RAR fragmentation in the winter. People with SAD lacked this increase in RAR fragmentation, and instead had earlier evening setting in the winter. Prospective and intervention studies with greater temporal resolution are warranted to ascertain how these seasonal behavioral differences relate to fatigue pathophysiology in SAD. Future research is needed to determine whether extending the winter active period, even in relatively fragmented bouts, could help reduce the fatigue symptoms common in SAD.

The effects of low-intensity narrow-band blue-light treatment compared to bright white-light treatment in seasonal affective disorder.

BACKGROUND: Ever since a new photoreceptor was discovered with a highest sensitivity to 470-490 nm blue light, it has been speculated that blue light has some advantages in the treatment of Seasonal Affective Disorder (SAD) over more traditional treatments. In this study we compared the effects of exposure to narrow-band blue light (BLUE) to those of broad-wavelength white light (BLT) in the treatment of SAD. METHODS: In a 15-day design, 45 patients suffering from SAD completed 30-min sessions of light treatment on 5 consecutive days. 21 subjects received white-light treatment (BLT, broad-wavelength without UV, 10 000 lx, irradiance 31.7 W/m2), 24 subjects received narrow-band blue light (BLUE, 100 lx, irradiance 1.0 W/m2). All participants completed weekly questionnaires concerning mood and energy levels, and were also assessed by means of the SIGH-SAD, which is the primary outcome measure. RESULTS: On day 15, SIGH-SAD ratings were significantly lower than on day 1 (BLT 73.2%, effect size 3.37; BLUE 67%, effect size 2.63), which outcomes were not statistically significant different between both conditions. LIMITATIONS: Small sample size. CONCLUSIONS: Light treatment is an effective treatment for SAD. The use of narrow-band blue light is equally effective as a treatment using bright white-light.

Self-perceived personality characteristics in seasonal affective disorder and their implications for severity of depression.

The personality traits Neuroticism and Extraversion may be involved in the development of seasonal affective disorder (SAD). However, the impact of personality traits on SAD severity and whether such self-reported traits fluctuate with season is unknown. We investigated the association between Neuroticism, as acquired in a symptom-free phase and depression severity in individuals with SAD and seasonal changes in personality traits in individuals with SAD compared to healthy controls. Twenty-nine individuals diagnosed with SAD and thirty demographically matched controls completed the NEO Personality Inventory-Revised and the Major Depression Inventory twice: in summer when individuals with SAD were symptom-free, and in winter when they experienced SAD symptoms. In summer, the groups scored similarly on their personality traits, and the controls did not score any different in winter compared to summer. High scores on Neuroticism in summer was associated with more severe depressive symptoms in winter in SAD individuals. In winter, individuals with SAD scored higher on Neuroticism and lower on Extraversion, both compared to controls and to their own summer scores. Our results support that Neuroticism may represent a vulnerability marker related to SAD, and during a depressive episode Neuroticism and Extraversion may be sensitive markers of SAD pathology.

Controlled trial evaluation of exposure duration to negative air ions for the treatment of seasonal affective disorder.

This study evaluated the effectiveness of 30 or 60min of daily exposure to high-density or to zero-density (placebo condition) negative air ions over 18 days on the symptoms of seasonal affective disorder (SAD) in 40 participants under controlled laboratory conditions. Exposure to high-density negative air ions was superior to zero-density negative air ions in alleviating depression and the atypical symptoms of SAD. Also, more subjects in the high-density negative air ions groups met two different clinical response criteria than did those in the zero-density groups. Within the high density treatment group, both the short and long daily exposure reduced SAD symptoms. Exposure to negative air ions produced no negative side effects, and no ozone was produced by the ion generators. In both the high-density negative air ions and zero-density negative air ions groups, a significant placebo effect was found for most clinical measures. Finally, for the high-density negative air ion groups, subjects with a morningness chronotype responded better to treatment with high-density negative air ions than did those with an eveningness chronotype.

Efficacy of bright light therapy in bipolar depression.

For 30 years, bright light therapy (BLT) has been considered as an effective, well-tolerated treatment for seasonal affective disorder (SAD). Because of low response rates, new treatment strategies are needed for bipolar depression (BD), which resembles SAD in certain respects. Few placebo-controlled studies of BLT efficacy have been carried out for BD. Accordingly, this study evaluates the efficacy and safety of BLT as an add-on treatment for BD. Thirty-two BD outpatients were randomly assigned to BLT (10000lx) or dim light (DL, < 500lx). During a two-week period, light was administered each morning for 30min. The Hamilton Rating Scale for Depression and the Montgomery-Ǻsberg Depression Rating Scale assessed clinical outcome, and the UKU Side Effects Rating Scale evaluated side effects. No significant difference was observed in baseline depression scores in the two groups. Response rates for BLT and DL were 81% and 19%, and remission rates were 44% and 12.5%, respectively. Analyses showed statistically significant reductions in depression scores for the BLT group compared with the DL group on all scales. Side effects were similar in both groups, with headache as the most common side effect. The results suggest that BLT is an effective and safe add-on treatment for BD.