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.

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 βindirect 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.

Seasonal affective disorder and engagement in physical activities among adults in Alaska

Seasonal affective disorder (SAD) is a type of depression in which symptoms occur during a particular season. While physical activity has been shown to improve symptoms for depression in general populations, the relationships between physical activity and experiences of seasonality and SAD remain underexplored. We conducted a survey with adult members of a recreational gym in Fairbanks, Alaska. The survey collected self-report data on sociodemographics, health behaviours, and elements of the Seasonal Pattern Assessment Questionnaire (SPAQ). Results indicate that 18.68% of our study participants meet the criteria for winter-pattern SAD and 43.96% meet the criteria for subsyndromal SAD ("winter blues"). We conducted two regressions to understand experiences of SAD and predictors of seasonality more generally. Gender was a significant predictor of SAD, with women more likely than men to experience SAD (p = .04). Being social at the gym, whether going to the gym with others or participating in activities with others, was associated with higher seasonality than being independent at the gym (p = .03). Younger age was also associated with higher seasonality (p < .001). This study contributes new insights about the relationship between engagement in physical activities and experiences of seasonality among adults in a northern latitude.

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: β = 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.

Predictive validity of the Seasonal Beliefs Questionnaire for discriminating between seasonal and nonseasonal major depressive disorder

The Seasonal Beliefs Questionnaire (SBQ) is a 26-item self-report measure of a winter seasonal affective disorder (SAD)-specific cognitive vulnerability consisting of maladaptive thoughts about the seasons, light availability, and weather conditions. In a known groups comparison, currently depressed adults with SAD had significantly higher SBQ scores than currently depressed adults with nonseasonal major depressive disorder (MDD) and healthy controls, and the MDD group had significantly higher SBQ scores than controls. Using that database, this study explored the predictive validity of using an SBQ cutoff score to differentiate SAD from MDD. Receiver operator characteristic curve analyses used SBQ total score to predict SAD versus MDD, SAD versus control, and MDD versus control status. The SBQ subscale combined score, derived from multivariable logistic regression with SBQ subscales, was examined as an alternative predictor. SBQ total score with a cutpoint of 132 had good predictive ability for distinguishing SAD from MDD (C-statistic = .792, sensitivity = .798, specificity = .794). The SBQ subscale combination score slightly improved predictive ability for the SAD/MDD distinction (C-statistic = .813), with better sensitivity (.930) but worse specificity (.571). In contrast, the score on a generic measure of depressogenic cognitive vulnerability, the Dysfunctional Attitudes Scale, was poor for differentiating SAD from MDD. SBQ total score was excellent in discriminating SAD cases from controls with a cutpoint of 121 (C-statistic = .962, sensitivity = .939, specificity .873), but had poor sensitivity for discriminating MDD cases from controls. Results support using the SBQ to screen for probable SAD in practice settings. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Seasonal Affective Disorder: Common Questions and Answers

Seasonal affective disorder is a mood disorder that is a subtype or qualifier of major depressive disorder or bipolar disorder in the Diagnostic and Statistical Manual of Mental Disorders. It is characterized by depressive symptoms that occur at a specific time of year (typically fall or winter) with full remission at other times of year (typically spring or summer). Possible risk factors include family history, female sex, living at a more northern latitude, and young adulthood (18 to 30 years of age). With the temporal nature of the mood episodes, diagnosis requires full remission when the specified season ends and two consecutive years of episodes in the same season. First-line therapy for seasonal affective disorder includes light therapy, antidepressants, and cognitive behavior therapy, alone or in combination. Commercial devices are available for administering light therapy or dawn simulation. The light intensity and duration of treatment depend on the device and the patient's initial response, but 2,500 to 10,000 lux for 30 to 60 minutes at the same time every day is typically effective. Lifestyle interventions, such as increasing exercise and exposure to natural light, are also recommended. If seasonal affective disorder recurs, long-term treatment or preventive intervention is typically indicated, and bupropion appears to have the strongest evidence supporting long-term use. Continuing light therapy or other antidepressants is likely beneficial, although evidence is inconclusive. Evidence is also inconclusive for psychotherapy and vitamin D supplementation.

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).

Treatment expectations for cognitive-behavioral therapy and light therapy for seasonal affective disorder: Change across treatment and relation to outcome

OBJECTIVE

To examine the dynamic relationship between treatment expectations and treatment outcome over the course of a clinical trial for winter seasonal affective disorder (SAD).

METHOD

Currently depressed adults with Major Depression, Recurrent with Seasonal Pattern (N = 177) were randomized to 6 weeks of group-delivered cognitive-behavioral therapy for SAD (CBT-SAD) or light therapy (LT). The majority were female (83.6%) and white (92.1%), with a mean age of 45.6 years. Treatment expectations for CBT-SAD and LT were assessed using a modification of the Treatment Expectancy and Credibility Survey (Borkovec & Nau, 1972). Depression severity was assessed using the Beck Depression Inventory-Second Edition (Beck, Steer, & Brown, 1996). All measures were administered at pretreatment, midtreatment, and posttreatment.

RESULTS

As treatment progressed, expectations for the treatment received increased across time steeply in CBT-SAD patients and moderately in LT patients. Collapsing across time, patients with higher treatment expectations had lower depression severity than those with lower treatment expectations. In a cross-lagged panel path analysis, there was a significant effect of treatment expectations at midtreatment on depression severity at posttreatment among CBT-SAD patients.

CONCLUSIONS

Treatment expectations changed across treatment, affected outcome, and should be assessed and monitored repeatedly throughout treatment. Findings suggest that treatment expectations at midtreatment are a mechanism by which CBT-SAD reduces depression, which should be replicated in SAD samples and examined for generalizability to nonseasonal depression. These findings underscore the importance of further research examining treatment expectations in mediating CBT's effects in depression and other types of psychopathology. (PsycINFO Database Record

The relation between chronotype and treatment outcome with light therapy on a fixed time schedule

BACKGROUND

Seasonal affective disorder (SAD) is characterized by recurrent episodes of major depression in a seasonal pattern. The therapy of choice is light therapy (LT). It is suggested that LT should be administered relative to the chronotype of the patient, with the optimal timing earlier for morning than for evening types. This study aims to retrospectively investigate the relation between chronotype and the effect of LT on a fixed time in the morning in a population of SAD patients.

METHODS

Data from four different studies conducted at the University Center of Psychiatry in Groningen, the Netherlands was used. Data from 132 patients was used (103 women). Depression score was determined by a structured interview (SIGH-SAD) prior to LT and after LT. Prior to LT morningness/eveningness preference of the patient was determined by the 'Morningness/Eveningness Questionnaire' (MEQ). All patients received LT at 8:00 AM at the clinic, independent of chronotype.

RESULTS

Patients had an average MEQ score of 51.5±8.2. There was no significant relationship between MEQ score and therapy success as measured with the SIGH-SAD (F2,129=0.05, ns). When patients were divided by chronotype (ranging from definite morning to moderate evening) no significant relation between MEQ score and therapy success was found (F2,129=0.02, ns).

LIMITATIONS

Retrospective design.

CONCLUSIONS

The lack of a significant relationship between chronotype, as measured with the MEQ, and therapy success with LT at a fixed timepoint may indicate that the anti-depressive effect of morning light in SAD patients is not explained by a phase shift of the biological clock.

[Antidepressant-resistant depression and the bipolar spectrum -- diagnostic and therapeutic considerations]

According to the results of epidemiological studies mood disorders with unipolar (major and minor depressive disorder; dysthymia) or bipolar features are among the most prevalent psychiatric disorders. These disorders with their frequent comorbidities (alcohol and/or drug use disorders, smoking, suicide, cardiovascular disorders) pose great public health challenge and cause substantial individual and familar burdens as well. Since SSRIs and other new antidepressant agents entered the market the possibilities to treat depression improved substantially but 25-35 percent of major depressives do not respond even to the second antidepressant trial but the rate of patients who are resistant after the third and fourth adequate antidepressant trial are around only 15-25 and 10 percent, respectively. Pharmacotherapy-resistant depression is a multicausal phenomenon. Along with its well-known risk-factors investigations of the past decade have revealed that unrecognised or hidden (subsyndromal or subthreshold) bipolarity is one of the most frequent causes of treatment resistance. In the case of bipolar depression (either as a part of syndromal bipolar I or II disorder or a subsyndromal manifestation) antidepressant monotherapy should be avoided and, instead of it, the administration of a mood stabilizer (primarily lithium and lamotrigine) or some atypical antipsychotics (preferably quetiapine) are recommended. If antidepressant is inevitably necessary in bipolar depression, we should use it always in combination with mood stabilizers or atypical antipsychotics.

Seasonal affective disorder, grief reaction, and adjustment disorder

Seasonal affective disorder is a subtype of other affective disorders. The most studied treatment is light therapy, although second-generation antidepressants are also an option. Grief reactions are normal for patients experiencing loss, and primary care providers (PCPs) should be aware of both the expected course of grief and the more severe symptoms that indicate complex grief. Adjustment disorder is a time-limited abnormal response to a stressor. PCPs can manage patients with adjustment disorder by arranging counseling, screening for suicidality, assessing for substance abuse, and ruling out other psychiatric diagnoses. At present there are no reliable data to suggest medication management.

Treatment of seasonal affective disorder

Seasonal affective disorder (SAD), winter type, is characterized by the regular annual onset of major depressive episodes during fall or winter, followed by spontaneous remission and sometimes hypomanic or manic episodes during spring and summer. SAD is clinically important, since approximately 2-5% of the general population in temperate climates are affected. Since the first description of the syndrome, researchers have made attempts to elucidate the pathophysiological background of SAD. Bright light therapy has been proposed as the treatment of choice for this disorder. However, numerous studies have also investigated suitable psychopharmacological treatments for SAD. This report is aimed to provide an overview on the clinical management and current therapeutic options for SAD.

[More than every tenth person have symptoms of seasonal affective disorder]

Seasonal affective disorder is a syndrome of classical depressive symptoms such as reduced energy, initiative and mood combined with atypical symptoms of increased appetite, weight and sleep duration. The symptoms recur each winter and disappear again in spring or early summer. The prevalence ranges from 1% to 10% in Scandinavian populations. Reduced light exposure, melatonergic and serotonergic disturbances are suggested pathogenetic factors. Light therapy offers convincing effect with minimal adverse effects and remains first-line treatment along with selective serotonin reuptake inhibitors.

Informing the symptom profile of complicated grief

BACKGROUND

Complicated Grief (CG) is under consideration as a new diagnosis in DSM5. We sought to add empirical support to the current dialogue by examining the commonly used Inventory of Complicated Grief (ICG) scale completed by 782 bereaved individuals.

METHODS

We employed IRT analyses, factor analyses, and sensitivity and specificity analyses utilizing our full sample (n = 782), and also compared confirmed CG cases (n = 288) to noncases (n = 377). Confirmed CG cases were defined as individuals bereaved at least 6 months who were seeking care for CG, had an ICG ≥ 30, and received a structured clinical interview for CG by a certified clinician confirming CG as their primary illness. Noncases were bereaved individuals who did not present with CG as a primary complaint (including those with depression, bipolar disorder, anxiety disorders, and controls) and had an ICG<25.

RESULTS

IRT analyses provided guidance about the most informative individual items and their association with CG severity. Factor analyses demonstrated a single factor solution when the full sample was considered, but within CG cases, six symptom clusters emerged: (1) yearning and preoccupation with the deceased, (2) anger and bitterness, (3) shock and disbelief, (4) estrangement from others, (5) hallucinations of the deceased, and (6) behavior change, including avoidance and proximity seeking. The presence of at least one symptom from three different symptom clusters optimized sensitivity (94.8%) and specificity (98.1%).

CONCLUSIONS

These data, derived from a diverse and predominantly clinical help seeking population, add an important perspective to existing suggestions for DSM5 criteria for CG.

The hypothalamic-pituitary-adrenal axis and serotonin abnormalities: a selective overview for the implications of suicide prevention

Suicidal behavior and mood disorders are one of the world's largest public health problems. The biological vulnerability for these problems includes genetic factors involved in the regulation of the serotonergic system and stress system. The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system that regulates the body's response to stress and has complex interactions with brain serotonergic, noradrenergic and dopaminergic systems. Corticotropin-releasing hormone and vasopressin act synergistically to stimulate the secretion of ACTH that stimulates the biosynthesis of corticosteroids such as cortisol from cholesterol. Cortisol is a major stress hormone and has effects on many tissues, including on mineralocorticoid receptors and glucocorticoid receptors in the brain. Glucocorticoids produce behavioral changes, and one important target of glucocorticoids is the hypothalamus, which is a major controlling center of the HPA axis. Stress plays a major role in the various pathophysiological processes associated with mood disorders and suicidal behavior. Serotonergic dysfunction is a well-established substrate for mood disorders and suicidal behavior. Corticosteroids may play an important role in the relationship between stress, mood changes and perhaps suicidal behavior by interacting with 5-HT1A receptors. Abnormalities in the HPA axis in response to increased levels of stress are found to be associated with a dysregulation in the serotonergic system, both in subjects with mood disorders and those who engage in suicidal behavior. HPA over-activity may be a good predictor of mood disorders and perhaps suicidal behavior via abnormalities in the serotonergic system.

Circadian rhythms and depression

BACKGROUND

Depression is a common disorder in primary care. Disruptions to the circadian rhythms associated with depression have received little attention yet offer new and exciting approaches to treatment.

OBJECTIVE

This article discusses circadian rhythms and the disruption to them associated with depression, and reviews nonpharmaceutical and pharmaceutical interventions to shift circadian rhythms.

DISCUSSION

Features of depression suggestive of a disturbance to circadian rhythms include early morning waking, diurnal mood changes, changes in sleep architecture, changes in timing of the temperature nadir, and peak cortisol levels. Interpersonal social rhythm therapy involves learning to manage interpersonal relationships more effectively and stabilisation of social cues, such as including sleep and wake times, meal times, and timing of social contact. Bright light therapy is used to treat seasonal affective disorders. Agomelatine is an antidepressant that works in a novel way by targeting melatonergic receptors.

[Diagnostic features, epidemiology, and pathophysiology of seasonal affective disorder]

Seasonal Affective Disorder (SAD) is characterized by patterns of major depressive episodes that occur and remit with the change of seasons. Two seasonal patterns have been identified: summer-type depression with typical depressive signs and symptoms, and winter-type depression with atypical features of depression. In the subsyndromal form of SAD (S-SAD) symptoms are milder, although vegetative symptoms are clinically significant. SAD needs to be differentiated from atypical depression, cyclothymic disorder, and dysthymia or chronic MDD which may be characterized by a winter worsening of symptoms. Full remission of symptoms must occur after the passing of the season for the disorder to merit the diagnosis of SAD. The mean prevalence of SAD in the temperate zone is 3 to 10%, while that of S-SAD is 6 to 20%. In Hungarian general population the occurrence of SAD is 4.6%, and S-SAD is 7.2%. The pathophysiology of SAD seems to be heterogeneous, studies suggest abnormal circadian rhythm and neurotransmitter function (phase shift hypothesis, role of serotonin, dopamin and norepinephrine). Genetic studies focusing on candidate genes involve 5-HTR2A, 5-HTR2C, DRD4, G protein, and clock-related genes.

Cultural variation in seasonal depression: cross-national differences in winter versus summer patterns of seasonal affective disorder

BACKGROUND

Research suggests that two dimensions of national culture, individualism-collectivism and power distance, predict affective responses to the seasonally varying levels of ambient sunlight that may underlie regular cycles of mood and behavior in Seasonal Affective Disorder (SAD). Specifically, negative affect is predicted by the diminished sunlight of fall-winter in countries higher in individualism and lower in power distance, and by the increased sunlight of spring-summer in countries lower in individualism and higher in power distance. This study tests whether individualism correlates positively, and power distance negatively, with the frequency of winter-SAD relative to that of summer-SAD.

METHOD

A search for studies reporting frequencies of both winter-SAD and summer-SAD identified 55 samples encompassing 18 countries and 38,408 participants, including 1931 with SAD.

RESULTS

The frequency of winter-SAD, relative to that of summer-SAD, correlated positively with individualism (r=.67, p=.001) and negatively with power distance (r=-.72, p=.0001). Countries in which winter-SAD was more common than summer-SAD were significantly more individualistic and less power-distant than countries in which summer-SAD was more common than winter-SAD. Results survived various tests of threats to validity.

LIMITATIONS

The study is limited by the quantity, quality, diversity, and representativeness of the research under review and by its correlational design.

CONCLUSIONS

Individualism and power distance are strongly related to the relative prevalence of winter-SAD and summer-SAD. Culture may play an important but previously overlooked role in the etiology of SAD.

Dates of birth and seasonal changes in well-being among 4904 subjects completing the seasonal pattern assessment questionnaire

BACKGROUND

Abnormal distributions of birthdates, suggesting intrauterine aetiological factors, have been found in several psychiatric disorders, including one study of out-patients with Seasonal Affective Disorder (S.A.D.). We investigated birthdate distribution in relation to seasonal changes in well-being among a cohort who had completed the Seasonal Pattern Assessment Questionnaire (SPAQ).

METHOD

A sample of 4904 subjects, aged 16 to 64, completed the SPAQ. 476 were cases of S.A.D. on the SPAQ and 580 were cases of sub-syndromal S.A.D. (S-S.A.D.). 92 were interview confirmed cases of S.A.D. Months and dates of birth were compared between S.A.D. cases and all others, between S.A.D. and S-S.A.D. cases combined and all others, and between interview confirmed cases and all others. Seasonality, as measured through seasonal fluctuations in well-being on the Global Seasonality Scores (GSS) of the SPAQ, was compared for all subjects by month and season of birth.

RESULTS

There was no evidence of an atypical pattern of birthdates for subjects fulfilling criteria for S.A.D., for the combined S.A.D./S-S.A.D. group or for interview confirmed cases. There was also no relationship between seasonality on the GSS and month or season of birth.

LIMITATIONS

Diagnoses of S.A.D. made by SPAQ criteria are likely to be overinclusive.

CONCLUSION

Our findings differ from studies of patients with more severe mood disorders, including psychiatric out-patients with S.A.D. The lack of association between seasonality and birthdates in our study adds credence to the view that the aetiology of S.A.D. relates to separable factors predisposing to affective disorders and to seasonality.

Season of birth modulates mood seasonality in humans

We investigate whether mood seasonality is modulated by season of birth. A sample of 1682 university students were administered the Seasonal Pattern Assessment Questionnaire. We found that subjects born during spring or summer months had significantly higher Global Seasonality scores than those born during autumn or winter months.

Is there seasonal variation in risk of Parkinson's disease?

Recent studies suggest that, for many adult-onset neurological diseases, persons born at a certain time of year are at higher risk of the disease. Small-scale studies have suggested that persons born in the spring may be at higher risk of developing Parkinson's disease (PD) late in life. There have also been suggestions that there are clusters of PD birth dates in the years of major influenza pandemics. To determine whether there is any seasonal variation in the birth dates of PD patients, we examined birth dates of 8,168 PD patients collected from subspecialty movement disorder clinics across Canada. Patterns of seasonality of birth were examined and compared with the general Canadian population. In addition, we compared counts of patients born in the years of major influenza pandemics with the number born in the surrounding years. We found no evidence of systematic seasonal variation in PD incidence by birth date, or of clustering of birth dates during influenza pandemic years in PD patients.

A randomized controlled trial of cognitive-behavioral therapy, light therapy, and their combination for seasonal affective disorder

This first controlled psychotherapy trial for seasonal affective disorder (SAD) compared SAD-tailored cognitive-behavioral therapy (CBT), light therapy (LT), and their combination to a concurrent wait-list control. Adults (N = 61) with major depression, recurrent with seasonal pattern, were randomized to one of four 6-week conditions: CBT (1.5-hr twice-weekly group therapy), LT (10,000-lux for 90-min/day with administration time individually adjusted), combined CBT + LT, or a minimal contact/delayed LT control (MCDT; LT following 6 weeks of monitoring). CBT, LT, and CBT + LT significantly and comparably improved depression severity relative to MCDT in intent-to-treat and completer samples. CBT + LT (73%) had a significantly higher remission rate than MCDT (20%). Using prospectively measured summer mood status to estimate the "functional" population, CBT + LT also had a significantly larger proportion of participants with clinically significant change over treatment compared with MCDT. The LT condition outcomes virtually replicated results from prior trials. CBT, alone or combined with LT, holds promise as an efficacious SAD treatment and warrants further study. If replicated, CBT + LT's remission rate would represent a clinically meaningful improvement over the 53% observed across LT studies.

Quality of life as an outcome indicator in patients with seasonal affective disorder: results from the Can-SAD study

BACKGROUND

Although a host of studies have now examined the relationship between quality of life (QoL) and non-seasonal depression, few have measured QoL in seasonal affective disorder (SAD). We report here on results from the Can-SAD trial, which assessed the impact of treatment with either antidepressant medication or light therapy upon QoL in patients diagnosed with SAD.

METHOD

This Canadian double-blind, multicentre, randomized controlled trial included 96 patients who met strict diagnostic criteria for SAD. Eligible patients were randomized to 8 weeks of treatment with either: (1) 10000 lux light treatment and a placebo capsule or (2) 100 lux light treatment (placebo light) and 20 mg fluoxetine. QoL was measured with the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) and the Medical Outcomes Study (MOS) Short-Form General Health Survey (SF-20) at baseline and 8 weeks.

RESULTS

Both intervention groups showed significant improvement in QoL over time with no significant differences being detected by treatment condition. Q-LES-Q scores increased significantly in seven of eight domains, with the average scores rising from 48 x 0 (S.D.=10 x 7) at baseline to 69 x 1 (S.D.=15 x 6) at week 8. Treatment-related improvement in QoL was strongly associated with improvement in depression symptoms.

DISCUSSION

Patients with SAD report markedly impaired QoL during the winter months. Treatment with light therapy or antidepressant medication is associated with equivalent marked improvement in perceived QoL. Studies of treatment interventions for SAD should routinely include broader indices of patient outcome, such as the assessment of psychosocial functioning or life quality.

Mood seasonality: a cross-sectional study of subjects aged between 10 and 25 years

BACKGROUND

Most of the earlier studies on mood seasonality were conducted in adults and there are few available data on children and adolescents. In two cross sectional surveys, we examined the role of age and gender on seasonal sensitivity in subjects aged 10 to 25 years.

METHODS

In survey one, the Seasonal Pattern Assessment Questionnaire for Children and Adolescents (SPAQ-CA) was administered to 1709 subjects (845 females and 864 males) from 10 to 17 years. In survey two, the Seasonal Pattern Assessment Questionnaire (SPAQ) was administered to 1867 subjects (1061 females and 806 males) from 18 to 25 years.

RESULTS

Only in survey one was a significant positive correlation found between age and Global Seasonality Score (GSS) (r=.29; p<.00001). Significant gender differences were found at age 14 years and above in survey one, and at all ages in survey two.

CONCLUSIONS

The results support the hypothesis that seasonal sensitivity is higher in female subjects.

Melatonin in mood disorders

The cyclic nature of depressive illness, the diurnal variations in its symptomatology and the existence of disturbed sleep-wake and core body temperature rhythms, all suggest that dysfunction of the circadian time keeping system may underlie the pathophysiology of depression. As a rhythm-regulating factor, the study of melatonin in various depressive illnesses has gained attention. Melatonin can be both a 'state marker' and a 'trait marker' of mood disorders. Measurement of melatonin either in saliva or plasma, or of its main metabolite 6-sulfatoxymelatonin in urine, have documented significant alterations in melatonin secretion in depressive patients during the acute phase of illness. Not only the levels but also the timing of melatonin secretion is altered in bipolar affective disorder and in patients with seasonal affective disorder (SAD). A phase delay of melatonin secretion takes place in SAD, as well as changes in the onset, duration and offset of melatonin secretion. Bright light treatment, that suppresses melatonin production, is effective in treating bipolar affective disorder and SAD, winter type. This review discusses the role of melatonin in the pathophysiology of bipolar disorder and SAD.

Controlled trial of naturalistic dawn simulation and negative air ionization for seasonal affective disorder

OBJECTIVE

This trial assessed two novel nonpharmaceutical treatments for winter depression-naturalistic dawn simulation and high-density negative air ionization-delivered during the final hours of sleep.

METHOD

The patients were 99 adults (77 women and 22 men) with the winter seasonal pattern of major depressive disorder (94 cases) and bipolar II disorder (five cases). Five parallel groups received 1) dawn simulation (0.0003-250 lux in the pattern of May 5 at 45 degrees north latitude); 2) a dawn light pulse (13 minutes, 250 lux, with an illuminant dose of 3.25x10(3) lux-minutes matched to the simulated dawn); 3) postawakening bright light (30 minutes, 10,000 lux); 4) negative air ionization at high flow rate (93 minutes, 4.5x10(14 )ions/second); or 5) ionization at low flow rate (93 minutes, 1.7x10(11) ions/second). The symptoms were assessed over 3 weeks with the Structured Interview Guide for the Hamilton Depression Rating Scale-Seasonal Affective Disorder Version.

RESULTS

Posttreatment improvement results were bright light, 57.1%; dawn simulation, 49.5%; dawn pulse, 42.7%; high-density ions, 47.9%; and low-density ions, 22.7% (significantly lower than the others). Contrary to the authors' hypothesis, analysis of variance failed to find superiority of dawn simulation to the dawn pulse or bright light. However, the dawn pulse led to a pattern of residual or exacerbated depressive symptoms similar to those seen in low-density ion nonresponders.

CONCLUSIONS

Naturalistic dawn simulation and high-density ionization are active antidepressants that do not require the effort of postawakening bright light therapy. They can be considered candidate alternatives to bright light or medication.

Seasonal affective disorder

Patients with seasonal affective disorder have episodes of major depression that tend to recur during specific times of the year, usually in winter. Like major depression, seasonal affective disorder probably is underdiagnosed in primary care settings. Although several screening instruments are available, such screening is unlikely to lead to improved outcomes without personalized and detailed attention to individual symptoms. Physicians should be aware of comorbid factors that could signal a need for further assessment. Specifically, some emerging evidence suggests that seasonal affective disorder may be associated with alcoholism and attention-deficit/hyperactivity disorder. Seasonal affective disorder often can be treated with light therapy, which appears to have a low risk of adverse effects. Light therapy is more effective if administered in the morning. It remains unclear whether light is equivalent to drug therapy, whether drug therapy can augment the effects of light therapy, or whether cognitive behavior therapy is a better treatment choice.

The association between seasonal and premenstrual symptoms is continuous and is not fully accounted for by depressive symptoms

Seasonal affective disorder (SAD) frequently co-occurs with premenstrual dysphoric disorder. Explanations of this comorbidity highlighting the cyclical nature of female sex hormones imply that seasonal and premenstrual symptoms should correlate positively even in nonclinical samples. In a sample of 91 female college students, we found a sizable positive correlation (r = .45; p < 0.001) between seasonal and premenstrual symptoms. This relation held up even in a subsample selected on the basis of not qualifying for SAD or subsyndromal SAD on a screening measure. Although the correlation was reduced when depressive symptom severity was statistically controlled, it remained positive and significant. Future research testing possible explanations of the co-occurrence of seasonal and premenstrual symptoms should incorporate the full range of severity on symptom variables, treating them as continua rather than solely as binary categories.

An open trial of light therapy in adult attention-deficit/hyperactivity disorder

OBJECTIVE

In adults with attention-deficit/ hyperactivity disorder (ADHD), a delayed sleep/ activity rhythm and/or seasonal mood symptoms may contribute significantly to core pathology and disability. This study examined whether a chronobiologically based treatment, i.e., morning bright light therapy (LT), might have utility as an adjunctive treatment for adult ADHD in the fall/ winter period.

METHOD

Twenty-nine adults with DSM-IV ADHD were administered a standard 3-week open trial of LT during the fall or winter months. Primary outcome measures included percentage reduction on the Brown Adult ADD Scale and the Conners' Adult ADHD Scale. Secondary measures were decrease in depression scores according to the Structured Interview Guide for the Hamilton Depression Rating Scale, Seasonal Affective Disorder version; improvements on various neuropsychological tests; and shift toward an earlier circadian preference as measured by the Horne-Ostberg Morningness-Eveningness questionnaire. Regression analyses determined which variables at baseline best predicted improvement on a given outcome measure and which variables changed in parallel with one another. The study was conducted from November 2003 through February 2004.

RESULTS

Morning bright light therapy was associated with a significant decrease in both subjective and objective measures of core ADHD pathology, improved mood symptoms, and a significant phase advance in circadian preference. Multiple regression showed that the shift toward an earlier circadian preference with LT was the strongest predictor of improvement on both subjective and objective ADHD measures. Neither baseline global seasonality scores nor baseline depression scores strongly predicted LT effects on most measures of ADHD.

CONCLUSION

These findings suggest that during the fall/winter period, LT may be a useful adjunct in many adults with ADHD. Strikingly, the strongest correlate of improvement in core ADHD pathology was a phase advance in circadian preference rather than alleviation of comorbid seasonal affective disorder, suggesting important clinical benefits of LT beyond the treatment of seasonal affective disorder.

Bright light therapy for seasonal affective disorder in Israel (latitude 32.6 degrees N): a single case placebo-controlled study

INTRODUCTION

We describe a patient diagnosed as having seasonal affective disorder (SAD, winter depression), an unlikely condition in Israel (latitude 32.6 degrees N), a country with relatively minor daylight photoperiodic changes between seasons.

METHOD

Case report.

RESULTS

A 46-year-old woman with a clinical picture of depression (Diagnostic and Statistical Manual of Mental Disorders diagnostic criteria for 'major depression with seasonal pattern') reacted positively to 3 weeks of daily bright light therapy of 10,000 lux/wide spectrum. She was asked to wear dark sunglasses during placebo sessions to accommodate an A-B-C single-case-design. The intervention resulted in an improvement of 74-80% in the Hamilton anxiety and depression scales (clinician-rated) and the Beck depression inventory, similar to results obtained in high latitude regions. The depression and anxiety levels returned close to baseline levels following 1 week of the placebo intervention.

CONCLUSION

Seasonal affective disorder is apparently not limited to certain latitudes. The effect of light therapy was short-lived after discontinuation of the treatment, with rapid relapse occurring in the placebo phase.

Personality and seasonal affective disorder: results from the CAN-SAD study

BACKGROUND

Personality factors have been implicated in seasonal affective disorder (SAD). The present study investigated the relationship between the five-factor model of personality (neuroticism, extraversion, openness, agreeableness, conscientiousness) and SAD.

METHODS

Ninety-five patients with SAD completed personality measures before and after treatment in a clinical trial and during the summer months. The personality scores of the SAD patients were compared with a matched group of non-seasonal depressed patients and published normative data. Stability and change in personality scores with changes in mood state were assessed. Personality dimensions were evaluated as possible predictors of treatment outcome.

RESULTS

SAD patients showed elevated openness scores relative to both non-seasonal depressed patients and norms. Their neuroticism scores were lower than non-seasonal depressed patients, but higher than norms. All personality dimensions showed large and highly significant test-retest correlations but several personality dimensions, particularly neuroticism and extraversion, also showed considerable change with changing mood state. None of the personality dimensions were significantly associated with treatment outcome.

LIMITATIONS

Personality assessment relied on self-report.

CONCLUSIONS

The personality profile of SAD patients differs from both non-seasonal depressed patients and norms. Elevated openness scores appear to be a unique feature of patients with SAD. Since mood state has a significant impact on personality scores, assessment of personality in SAD patients should ideally be conducted when they are in remission. Further investigation of the relationship between personality and SAD, especially the potential significance of elevated openness scores, is warranted.

Seasonality of mood disorders in adults with lifetime attention-deficit/hyperactivity disorder (ADHD)

BACKGROUND

The objective of this study was to estimate the prevalence of Seasonal Affective Disorder (SAD) in adults with lifetime Attention-Deficit/Hyperactivity Disorder (ADHD).

METHOD

Patients eligible for this study had lifetime impairing symptoms of ADHD and a current and/or past co-morbid mood disorder according to their medical record. The Seasonal Pattern Assessment Questionnaire (SPAQ) was administered by a telephone interview to assess seasonality.

RESULTS

The overall rate of SAD in this clinical population of adults with ADHD was estimated at 27%. Females were more at risk to develop SAD than men.

LIMITATIONS

The SPAQ is a screening, not a diagnostic instrument.

CONCLUSIONS

SAD symptoms are frequently comorbid with ADHD in adults. These results have clinical relevance for the recognition and treatment of SAD with bright light therapy in adults with ADHD.

Light therapy for seasonal affective disorder with blue narrow-band light-emitting diodes (LEDs)

BACKGROUND

While light has proven an effective treatment for Seasonal Affective Disorder (SAD), an optimal wavelength combination has not been determined. Short wavelength light (blue) has demonstrated potency as a stimulus for acute melatonin suppression and circadian phase shifting.

METHODS

This study tested the efficacy of short wavelength light therapy for SAD. Blue light emitting diode (LED) units produced 468 nm light at 607 microW/cm2 (27 nm half-peak bandwidth); dim red LED units provided 654 nm at 34 microW/cm2 (21 nm half-peak bandwidth). Patients with major depression with a seasonal pattern, a score of > or =20 on the Structured Interview Guide for the Hamilton Depression Rating Scale-SAD version (SIGH-SAD) and normal sleeping patterns (routine bedtimes between 10:00 pm and midnight) received 45 minutes of morning light treatment daily for 3 weeks. Twenty-four patients completed treatment following random assignment of condition (blue vs. red light). The SIGH-SAD was administered weekly.

RESULTS

Mixed-effects analyses of covariance determined that the short wavelength light treatment decreased SIGH-SAD scores significantly more than the dimmer red light condition (F = 6.45, p = .019 for average over the post-treatment times).

CONCLUSIONS

Narrow bandwidth blue light at 607 microW/cm2 outperforms dimmer red light in reversing symptoms of major depression with a seasonal pattern.

Distinct seasonality of depressive episodes differentiates unipolar depressive patients with and without depressive mixed states

BACKGROUND

The bipolar nature of unipolar depression with depressive mixed states (DMX) needs further validation studies. The seasonality of depressive episodes is indicated to be different between unipolar and bipolar depressions. We therefore explored the seasonal pattern of depressive episodes in unipolar depressive patients with DMX.

METHODS

The subjects were 958 consecutive depressive inpatients for a 6-year period. For defining DMX, previously validated operational criteria were used (2 or more of 8 manic or mania-related symptoms: flight of idea, logorrhea, aggression, excessive social contact, increased drive, irritability, racing thoughts, and distractibility). Onsets of the index depressive episodes during each of the 12 calendar months were summed up over the 6-year for bipolar depressive patients (N = 95), and unipolar depressive patients with (N = 77) and without DMX (N = 786) separately. An appropriate statistic was used for testing seasonality.

RESULTS

A significant seasonal variation with a large peak in spring was recognized in unipolar depression without DMX, while both bipolar depression and unipolar depression with DMX had a significant fall peak. The monthly distribution of depressive episodes was significantly different between unipolar depression without DMX and other 2 diagnostic categories. Similar results were obtained in separate analyses for each gender.

LIMITATIONS

Further replication study using an epidemiological or outpatient sample is needed. Bipolar I and II patients were combined due to a small number of bipolar II patients in this sample.

CONCLUSION

Unipolar depression with DMX has a seasonal pattern similar to bipolar depression. The finding provides further evidence of the bipolar nature of unipolar depression with DMX.

Psychic and somatic anxiety differentially predict response to light therapy in women with seasonal affective disorder

OBJECTIVE

To examine whether psychic and/or somatic anxiety predict responsiveness to light therapy in women with winter Seasonal Affective Disorder (SAD).

DESIGN

Eighty-one women with SAD were administered a standard 10-day trial of light therapy administered for one-half hour in the early morning. Using a multiple regression model, baseline somatic and psychic anxiety item scores were used to predict percentage change scores on the 29-item SIGH-SAD post treatment. Baseline scores for weight gain, hypersomnia and the total SIGH-SAD were also included as predictor variables.

RESULTS

The regression model was highly significant (F=4.63, df=5,75; p=.001; model R(2)=.236), with both psychic anxiety and somatic anxiety contributing significantly to the model. Consistent with prior work using anti-depressant medication in non-seasonal depression, psychic anxiety was positively correlated with outcome, while somatic anxiety negatively predicted outcome.

CONCLUSIONS

In SAD, psychic and somatic anxiety scores at baseline appear to be independent and opposite predictors of light therapy response. These effects were independent of baseline scores for weight gain and hypersomnia, two previously established predictors of response to light. These findings may be an important consideration in the design and interpretation of light therapy studies of SAD.

Illuminating the impact of habitual behaviors in depression

Researchers have hypothesized that habitual behaviors are zeitgebers for the circadian clock. However, few studies have examined the relationship between habitual behaviors and light, the strongest zeitgeber. Depression is an ideal model in which to explore this relationship because depression is a disorder associated with disruptions in circadian biological activity, sleep, and social rhythms (or patterns of habitual behaviors). We hypothesized that individuals with fewer habitual behaviors have less average exposure to light from morning rise time to evening bedtime and that a reduction in light exposure increases the likelihood of depression. Thirty-nine depressed and 39 never-depressed participants wore an ambulatory light monitor and completed the Social Rhythm Metric over the course of 2 weeks. Linear and logistic regression techniques were used to calculate regression coefficients, and confidence limits based on the distribution of the product of two normal random variables were computed to test the significance of the mediation effect. Infrequent habitual behaviors were associated with a decrease in average levels of light exposure, and low levels of light increased the likelihood of depression. This mediation effect was partial; the overall number of habitual behaviors had a direct relationship with depression above and beyond the association with light exposure. Longitudinal studies are needed to empirically demonstrate the direction of relationships between each of the variables tested.

The diagnosis, symptomatology, and epidemiology of seasonal affective disorder

The operational criteria for seasonal affective disorder (SAD) have undergone several changes since first proposed in 1984. SAD is currently included as a specifier of either bipolar or recurrent major depressive disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. The International Classification of Diseases, Tenth Edition has provisional diagnostic criteria for SAD. The most characteristic quality of SAD is that the symptoms usually present during winter and remit in the spring. Furthermore, the symptoms tend to remit when the patients are exposed to daylight or bright light therapy. The cognitive and emotional symptoms are as in other types of depression but the vegetative symptoms are the reverse of classic depressive vegetative symptoms, namely increased sleep and increased appetite. SAD is a common condition, but the exact prevalence rates vary between different studies and countries and is consistently found to be more common in women and in youth. SAD probably possibly occurs in children although not as commonly as in young adults. Some studies have found that certain ethnic groups who live at high northern latitudes may have adapted to the long arctic winter.

Are seasonality of mood and eveningness closely associated?

It has been suggested that being an "evening type" might enhance susceptibility to non-seasonal and seasonal affective disorders (SAD). In a survey and a prospective study, we examine the relationship between mood seasonality and circadian typology. In the survey study, the Morningness-Eveningness Questionnaire (MEQ) and the Seasonal Pattern Assessment Questionnaire (SPAQ) were administered to 1715 university students from Spain and Italy. In the prospective study, 18 subjects, selected from the Italian sample, self-assessed their mood monthly for over a year. A slight but significant negative correlation between the MEQ score and the Global Seasonality Score was found in the survey study, with a significantly higher incidence of evening versus morning types among the students with seasonal depression. These results were not replicated when the Spanish sample was analysed separately. In the prospective study, evening types did not present a higher annual range of mood variations than morning types. Caution should be exercised in ascribing eveningness as a risk factor in SAD since other underestimated factors, including social-cultural conditions, might be involved in the pathogenesis of mood seasonality.

Quality of life in patients with seasonal affective disorder: summer vs winter scores

OBJECTIVE

To compare perceived quality of life (QoL) in patients diagnosed with seasonal affective disorder (SAD) during the winter and summer months.

METHODS

Twenty-six patients who were enrolled in an ongoing multicentre study in Canada completed 2 measures of QoL (the 20-item Medical Outcomes Study Short-Form General Health Survey [SF-20] and the Quality of Life Enjoyment and Satisfaction Questionnaire, [Q-LES-Q]) during the winter, when suffering from depression, and again during the summer months.

RESULTS

Both general and health-related QoL scores were significantly improved in patients with SAD during the summer months, with scores for the most part falling within normal range.

CONCLUSIONS

Perceived QoL in patients with SAD is markedly impaired during the winter months but shows a substantial rebound during the summer months. The findings of this study provide further evidence that SAD is a distinct diagnostic entity.

Personality of seasonal affective disorder analyzed by Tri-dimensional Personality Questionnaire

BACKGROUND

Although there have been numerous reports in personality of mood disorders, there have been few reports in regard with personality of winter seasonal affective disorder (SAD). Furthermore, no reports have been published concerning summer SAD personality characteristics. Thus, this study was conducted to assess the personality of winter and summer SAD using Tri-dimensional Personality Questionnaire (TPQ) that have been used in a variety of mental disorders.

METHODS

A total of 6135 Japanese were evaluated with TPQ, the Seasonal Pattern Assessment Questionnaire (SPAQ) and the Self-rating Depression Scale (SDS). Winter, summer and non-SAD groups were classified by SPAQ. We compared the difference of personality trait among these three groups in consideration of gender, age and SDS score influence.

RESULTS

Winter SAD demonstrated higher "Novelty Seeking" and "Harm Avoidance"; summer SAD showed higher "Harm Avoidance" than the non-SAD group. "Harm Avoidance" in both SAD groups was re-analyzed using SDS score as a covariate, and "Novelty Seeking" in winter SAD using age as a covariate. As a result, the significance of high "Novelty Seeking" and high "Harm Avoidance" in winter SAD was excluded. However, "Harm Avoidance" remained the significant difference between summer and non-SAD.

LIMITATION

SAD was diagnosed only by SPAQ and not by interview. The state-dependency of "Harm Avoidance" was not confirmed in identical patients over lapse of time.

CONCLUSION

Patients with winter SAD have high "Harm Avoidance" dependent on the depressive state that is in accordance with non-seasonal depression. Patients with summer SAD have high "Harm Avoidance" possibly independent from the depressive state.