Validity of seasonal pattern as a modifier for recurrent mood disorders for DSM-IV

Effect of MAOA DNA Methylation on Human in Vivo Protein Expression Measured by [11C]harmine Positron Emission Tomography

BACKGROUND

Epigenetic modifications like DNA methylation are understood as an intermediary between environmental factors and neurobiology. Cerebral monoamine oxidase A (MAO-A) levels are altered in depression, as are DNA methylation levels within the MAOA gene, particularly in the promoter/exon I/intron I region. An effect of MAOA methylation on peripheral protein expression was shown, but the extent to which methylation affects brain MAO-A levels is not fully understood.

METHODS

Here, the influence of MAOA promoter/exon I/intron I region DNA methylation on global MAO-A distribution volume (VT), an index of MAO-A density, was assessed via [11C]harmine positron emission tomography in 22 patients (14 females) suffering from seasonal affective disorder and 30 healthy controls (17 females).

RESULTS

No significant influence of MAOA DNA methylation on global MAO-A VT was found, despite correction for health status, sex, season, and MAOA variable number of tandem repeat genotype. However, season affected average methylation in women, with higher levels in spring and summer (Puncorr = .03). We thus did not find evidence for an effect of MAOA DNA methylation on brain MAO-A VT.

CONCLUSIONS

In contrast to a previous study demonstrating an effect of methylation of a MAOA promoter region located further 5' on brain MAO-A, MAOA methylation of the region assessed here appears to affect brain protein levels to a limited extent at most. The observed effect of season on methylation levels is in accordance with extensive evidence for seasonal effects within the serotonergic system.

CLINICALTRIALS.GOV IDENTIFIER

NCT02582398 (https://clinicaltrials.gov/ct2/show/NCT02582398).

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

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

Seasonality and personality: a prospective investigation of Five Factor Model correlates of mood seasonality

The aim of the present study was to explore winter pattern seasonality of mood by investigating its Five Factor Model (FFM) correlates. The study was an advance on existing research in that seasonality was measured not as a retrospective self‐description of mood variation, but as a prospective pattern of current mood states in winter and summer (across two years). Based on contemporary theorizing about the structure and function of mood, Positive Affect (PA) was the mood construct selected for measurement. A seasonality score was calculated for each participant as the difference between summer mood levels and winter mood levels. The NEO‐FFI was administered at all four waves. Three hundred and three respondents from a random community sample in Melbourne, Australia, provided complete data. Regression analyses found that the adaptive trait Openness to Experience (O) was specifically associated with the tendency towards lowered mood in winter relative to summer. The vulnerability trait Neuroticism (N) was not a directional predictor of winter pattern seasonality, but was the sole predictor of absolute seasonality score. Findings are discussed in terms of two affective processes that may be involved in mood variation across the seasonal time frame: adaptive environmental sensitivity and endogenous mood variability. Copyright © 2002 John Wiley & Sons, Ltd.

No evidence of seasonal variation in mild forms of depression

BACKGROUND AND OBJECTIVES

Seasonal Affective Disorder (SAD) is ubiquitous in popular culture and has influenced psychiatric diagnosis with the inclusion of the seasonal pattern modifier for the Major Depressive Episode in DSM. However, recent research has not supported the association of Major Depressive Episode with seasonal changes. The present study was conducted to determine if a seasonally-related pattern of occurrence of mild variants of depression could be demonstrated in a population-based study.

METHODS

This is a cross-sectional U.S. survey of adults who completed the PHQ-8 Depression Scale with mild depression defined using a PHQ-8 cut score and a second model based on the DSM-5 diagnosis, Depression with insufficient symptoms. Regression models were used to determine if either variant of mild depression was related to season, latitude, or measures of daylight hours.

RESULTS

Neither measure of mild depression was related to daylight hours or its proxy measures.

LIMITATIONS

Screening instruments for depression, even if consistent with DSM-5 diagnostic criteria, do not allow a formal diagnosis of depression or the exclusion of similar-appearing disorders. Current depression symptoms but not duration of depressive episode is measured.

CONCLUSIONS

Mild depression is not related to seasonal changes or proxy measures of light exposure. The findings cast doubt on light deficiency as a causal factor of depressive disorders, which underpins the inclusion of the seasonal pattern modifier in DSM-5 and light supplementation as a treatment modality.

Circadian rhythms and depression: human psychopathology and animal models

Most organisms (including humans) developed daily rhythms in almost every aspect of their body. It is not surprising that rhythms are also related to affect in health and disease. In the present review we present data that demonstrate the evidence for significant interactions between circadian rhythms and affect from both human studies and animal models research. A number of lines of evidence obtained from human and from animal models research clearly demonstrate relationships between depression and circadian rhythms including (1) daily patterns of depression; (2) seasonal affective disorder; (3) connections between circadian clock genes and depression; (4) relationship between sleep disorders and depression; (5) the antidepressant effect of sleep deprivation; (6) the antidepressant effect of bright light exposure; and (7) the effects of antidepressant drugs on sleep and circadian rhythms. The integration of data suggests that the relationships between the circadian system and depression are well established but the underlying biology of the interactions is far from being understood. We suggest that an important factor hindering research into the underlying mechanisms is the lack of good animal models and we propose that additional efforts in that area should be made. One step in that direction could be the attempt to develop models utilizing diurnal animals which might have a better homology to humans with regard to their circadian rhythms. This article is part of a Special Issue entitled 'Anxiety and Depression'.

[Validity of vascular depression as a specific diagnostic: a review]

INTRODUCTION

A number of authors have suggested that cerebrovascular disease may predispose, precipitate, or perpetuate some geriatric depressive syndromes. These "vascular depressions" may result from damage of striato-pallido-thalamo-cortical pathways which frequently occurs in cerebrovascular disease.

METHOD

We have searched the English and French literature published between 1996 (when the "vascular depression" hypothesis was first stated) and December 2004 through the Medline computer database and examined the validity of the concept of "vascular depression" thanks to four levels of validity: face validity, descriptive validity, construct validity and predictive validity. The face validity is the extent to which experts agree about the existence of a nosological entity.

RESULTS

The reviews published in this field broadly support the concept of "vascular depression" as a specific disorder. However many authors highlighted the fact that depression has been shown to precede vascular diseases and that depression and vascular diseases may both share some pathogenic or genetic determinants. These interactive and co-morbid relationships between depression and cerebrovascular diseases are difficult to disentangle. The descriptive validity refers to the degree of the clinical specificity of a disorder. It appears only moderate regarding the clinical studies carried out on this issue. However, a late-onset, the absence of a family history of mental illness, the lack of insight, lassitude, psychomotor retardation, a greater disability and particular neuropsychological dysfunctions may be associated with vascular depression. The construct validity, which refers to the degree to which the physiopathological processes involved in an illness are understood, appears difficult to establish because of the complex interactive relationships between cerebrovascular disease and depression. However, cerebrovascular diseases may contribute to the occurrence of depressive symptoms independently of its psychosocial burden. The predictive validity refers to the degree to which a syndrome is characterized by a specific response to treatment or a specific natural history. As regards response to treatment, vascular depression appears rather specific in the sense of a worse response to antidepressants and electroconvulsive therapy. The studies on the natural history of vascular depression lead to inconsistent results. According to some authors, this relative resistance to treatment may be explained by structural rather than functional, and thus potentially irreversible disruption in neural networks.

CONCLUSION

In conclusion, the systematic review of the validity of vascular depression broadly supports this concept. However, further studies are needed to decipher the relationships between depression and cerebrovascular disease. Finally, we suggest that it could be more relevant for future researches in this field if the diagnostic criteria for vascular depression were narrowed and required the presence of both neuro-imaging changes and cerebrovascular disease.

A comparison of personality function among patients with seasonal depression, nonseasonal depression, and nonclinical participants

Although a large body of research has accumulated concerning the relationship between nonseasonal depression and personality, comparatively few studies have examined the relationship between seasonal affective disorder (SAD) and personality. This study compared dimensional aspects of personality in patients diagnosed with SAD (N = 60), nonseasonal depression (N = 273), and nonclinical controls (N = 297) using the Dimensional Assessment of Personality Pathology (DAPP-BQ; Livesley & Jackson, in press). Analysis by ANCOVA indicated that significant between-group differences occurred in several of the 18 DAPP-BQ dimensions, with patients with SAD exhibiting personality psychopathology that was intermediate between the nonclinical sample and patients with nonseasonal depression. The results demonstrated that the traits associated with seasonal and nonseasonal depression differ in degree, not kind.

How common is seasonal affective disorder in temperate Australia? A comparison of BDI and SPAQ estimates

BACKGROUND

The frequency of winter Seasonal Affective Disorder (SAD) in temperate Australia is unknown.

METHOD

A random community sample in Melbourne completed four waves of data collection (winter and summer across two years). The presence of winter SAD was estimated in three ways: (i) self-reports on the Seasonal Pattern Assessment Questionnaire (SPAQ), (ii) evidence of significant depression as assessed on the Beck Depression Inventory (BDI) in winters and not summers, and (iii) a combined definition based on both SPAQ and BDI estimates.

RESULTS

Of 1080 questionnaires originally mailed, complete four-wave BDI data was obtained from 380 respondents, and complete SPAQ data from 297. The frequency of winter SAD as estimated from SPAQ data was 0.7% and from BDI data was 0.5%. One participant (1 of 297, 0.3%) met BDI criteria and approached caseness on SPAQ criteria.

LIMITATIONS

A larger sample is necessary to definitively estimate prevalence.

CONCLUSIONS

Winter SAD appears to be rare in temperate Australia. The best estimate from the current study (0.3%) is an advance on simple self-report estimates and provides a necessary reference point for clinicians and researchers.

The Seasonal Pattern Assessment Questionnaire as a measure of mood seasonality: a prospective validation study

The aim of this study was to test the validity of the Seasonal Pattern Assessment Questionnaire (SPAQ) as a measure of winter pattern seasonality of mood in the general population. The criterion was four repeated measurements of mood, collected in summer and winter each year for 2 years in a longitudinal questionnaire study. To account for the imperfect reliability of SPAQ reports, the SPAQ was completed on two occasions, and aggregate SPAQ variables created. Three variables from the SPAQ were tested for their correlation with prospectively measured lowering of mood in winter: seasonal pattern type, Global Seasonality Score (GSS) and self-reported problems with seasonal variation. The sampling frame was the electoral roll in a suburban region of Melbourne, Australia. Complete four-wave data were obtained from 304 respondents (53.9% female). Seasonal pattern type (self-report as feeling worst in winter months) was the only SPAQ variable to show a significant association with prospectively measured winter pattern seasonality of mood. It is provisionally concluded that the SPAQ can function as a measure of seasonality of mood in the normal population, but that validity has only been confirmed for the relatively gross variable of seasonal pattern type.

Seasonal depression: the dual vulnerability hypothesis revisited

OBJECTIVE

In DSM-IV, winter seasonal affective disorder (SAD) is classified as a seasonal pattern of recurrent major depressive episodes in winter with full remission of symptoms in summer. However, other groups with "winter depression" have been identified, including patients with incomplete summer remission (ISR) and subsyndromal SAD (sub-SAD, winter depressive symptoms that do not meet criteria for major depression). In this study, we compare the clinical characteristics of these three seasonal groups and their response to light therapy.

METHOD

558 patients assessed at a specialized SAD Clinic were diagnosed using DSM-III-R or DSM-IV criteria. Clinical information was recorded using a checklist at index assessment. A subset of patients (N=192) were treated with an open, 2 week trial of light therapy using a 10000 lux fluorescent light box for 30 min per day in the early morning. Patients were assessed before and after treatment with the 29 item modified Hamilton Depression Rating Scale and clinical response was defined as greater than 50% improvement in scores.

RESULTS

The rates of some melancholic symptoms, anxiety, panic, suicidal ideation, and family history of mood disorder were lowest in the sub-SAD group. The clinical response rates to light therapy were highest in the sub-SAD group (N=32, 78%), intermediate in the SAD group (N=113, 66%), and lowest in the ISR group (N=47, 51%).

LIMITATIONS

This was a retrospective study of patients seen in a specialty clinic, although information was obtained in a standardized format. The light therapy trial had an open design so that placebo response could not be determined.

CONCLUSIONS

There are differences in both the patterns of clinical symptoms and the response to light therapy in these three groups with winter depression. These results are consistent with a dual vulnerability hypothesis that considers these groups to result from interaction of separate factors for seasonality and depression.

Psychosocial interventions for bipolar disorder

The limitations of pharmacotherapy and the emergence of data supporting a role for psychosocial factors in the course of bipolar disorder have led to increased interest in the use of psychosocial interventions to improve outcomes. Although this area of study has suffered from a lack of systematic data, preliminary evidence suggests that the combined use of psychosocial interventions and medication is superior to pharmacologic treatment alone. Further research is necessary to identify and the psychosocial risk factors associated with bipolar disorder to design effective interventions to diminish their effects and improve outcome. The introduction of formal, manual-based psychotherapeutic interventions that include specific educational components has been particularly promising.

Seasonal mood change and personality: an investigation of genetic co-morbidity

Clinical observations and empirical studies suggest that Seasonal Affective Disorder (SAD) is related to personality. The present study estimates the genetic and environmental correlations between the Global Seasonality Score (GSS) from the Seasonal Pattern Assessment Questionnaire and personality measures, assessed using the NEO Five Factor Inventory (NEO-FFI) and the Dimensional Assessment of Personality Pathology (DAPP) in a volunteer sample of 163 monozygotic (MZ) pairs (102 female and 61 male pairs) and 134 dizygotic (DZ) pairs (70 female, 38 male and 26 opposite-sex pairs). Large genetic correlations were found between the GSS and NEO-FFI Neuroticism (0.52: 95% CI = 0.36-0.71) and DAPP-BQ Cognitive Dysregulation (0.50: 95% CI = 0.30-0.71), Affective Lability (0.49: 95% CI = 0.29-0.77), Anxiousness (0.37: 95% CI = 0.18-0.55) and Stimulus Seeking (0.45: 95% CI = 0.25-0.64) scales. The genetic correlations with the remaining scales, such as Extraversion (0.06: 95% CI = -0.16-0.26), Compulsivity (-0.09: 95% CI = -0.31-0.12) and Submissiveness (0.15: 95% CI = -0.05-0.34) were uniformly small. All environmental correlations between the GSS and personality scales were < or = 0.19. These results provide evidence that the observed correlations between these seasonality and personality dimensions are attributable to common genetic factors and that environmental influences are domain specific.

Gender differences in the heritability of seasonal mood change

The study estimated gender differences in the magnitude of genetic and environmental influence in seasonal mood change. The self-report Seasonal Pattern Assessment Questionnaire (SPAQ) was completed by 339 volunteer reared-together twinpairs (187 monozygotic pairs, 152 dizygotic pairs) and analysed using biometric genetic models. The SPAQ yields a global seasonality score (GSS) which is an index of change in sleep patterns, social activities, mood, weight, appetite, and energy level. The GSS was significantly heritable among males and females, estimated to account for 69% and 45% of the total variance, respectively. For the individual symptoms, changes in sleep patterns, social activities, mood, appetite, and energy levels were accounted for primarily by additive genetic effects in both males (median, 45.5%) and females (median, 30.5%). For both sexes, weight changes were not heritable. Sex-by-genotype analyses suggested that the genetic factors influencing female seasonality may not be the same as those influencing male seasonality.

Seasonal affective disorder in Australia: is photoperiod critical?

OBJECTIVES

Seasonal affective disorder (SAD) is a variant of recurrent depression in which episodes are linked to a particular season, typically winter. SAD is understood as the extreme end of a continuum of seasonality in the general population. Photoperiod (the timing and duration of daylight) has been assumed to be aetiologically critical. The present research used a survey design to investigate the assumed centrality of photoperiod for SAD/seasonality in Australia. Two hypotheses were tested: that self-reported seasonality does not increase further from the equator and that seasonality does not stand alone from non-seasonal neurotic complaints.

METHOD

The sampling frame used was adult females on the Australian Twin Registry roll. A sample of 526 women residing across the latitudes of Australia responded to a survey based around the Seasonal Pattern Assessment Questionnaire (SPAQ). The SPAQ asks respondents to retrospectively report on season-related changes in mood and behaviour. The survey also contained three questionnaire measures of neurotic symptoms of anxiety and depression: the General Health Questionnaire (GHQ), the Community Epidemiological Survey for Depression (CES-D) and the State-Trait Anxiety Inventory-Trait (STAI-T).

RESULTS

Self-reported seasonality did not correlated with latitude (r = 0.01, NS). On the other hand, a substantial relationship was found between seasonality and each of the measures of non-seasonal complaints: GHQ (r = 0.35, p < 0.001); CES-D (r = 0.35, p < 0.001); and STAI-T (r = 0.30, p < 0.001).

CONCLUSIONS

Within the limitations of a design based on retrospective self-report, the findings of the present study suggest that the diathesis for SAD/seasonality may not be photoperiod-specific. At least in Australia, there is provisional support for the proposal that human seasonality may have a broader psychological component. The findings are discussed in terms of established research into normal mood, trait personality and non-seasonal depression.

DSM-III-R personality disorders in seasonal affective disorder: change associated with depression

Forty-five patients with winter Seasonal Affective Disorder (SAD) completed the Personality Diagnostic Questionnaire-Revised (PDQ-R) in a depressed state before starting therapy (light or medication), and again 14 weeks later when the scores on the Montgomery Asberg Depression Rating Scale (MADRS) had been reduced by an average of 74%. Prevalence and pattern of personality disorders (PDs) before treatment were similar to that found in patients with nonseasonal major depressive disorder (MDD) during a depressive episode. Number of categorical diagnoses were lower at follow-up for most PDs, but differences were not statistically significant. However, for dimensional scores (number of positive DSM-III-R criteria) significant changes were found for schizotypal, histrionic, narcissistic, and obsessive-compulsive PD, and for total dimensional score in cluster B and total score for all PDs. These changes differ from findings in similar studies of outpatients with nonseasonal MDD. Whether this indicates a specific pattern of change for patients with SAD is discussed. Multiple regression analysis showed a significant association between changes in positive PD criteria between the depressed and nondepressed state and change in depression score. No significant relationship was found between changes in PD criteria and Global Seasonality Score (GSS), a measure reflecting the sum of ratings of seasonal variation in sleep length, social activity, mood, weight, appetite, and energy level.

The validity of atypical depression in DSM-IV

Atypical depression has been included in the DSM-IV as an episode specifier of major depressive episodes and dysthymia. This report will review evidence for the clinical validity of atypical depression using operational criteria for the validation of clinical syndromes. English language articles between 1969 and March 1996 were found using a computerized and manual reference search and were selected according to the following criteria: (1) primary research, (2) definition of atypical depression, which includes depression and not anxiety alone, and (3) relevance of data for validation of atypical depression. Studies were evaluated on Kendall's six criteria for establishing clinical validity. There are supporting data for diagnostic validity of atypical depression in the criteria of clinical description and differential treatment response, with atypical depression having a superior response to monoamine oxidase (MAO) inhibitors compared to tricyclic antidepressants. There is still only limited support for the validity of atypical depression in the criteria of pathophysiology, points of rarity with other similar diagnoses, distinctive course and outcome, and genetics. Based on the current evidence, atypical depression is a useful diagnostic concept, particularly for predicting differential drug response, but further research is required to conclusively demonstrate its validity as a clinical syndrome.

Validation of the Seasonal Pattern Assessment Questionnaire (SPAQ)

The validity of the Seasonal Pattern Assessment Questionnaire (SPAQ) was examined by interviewing 81 individuals who had participated in an earlier community survey of seasonal affective disorder (SAD) in Iceland. When SAD and subsyndromal SAD (S-SAD) were combined into a 'winter problem' group, the questionnaire's sensitivity, specificity and positive predictive value for that group were 94%, 73% and 45%, respectively. The SPAQ discriminated poorly between SAD and S-SAD, and hence it had a poor case-finding ability for SAD. Clinical evaluation verified a diagnosis of SAD in individuals who had no previous information about this syndrome. The questionnaire furthermore identified a group of individuals who had generalized anxiety and marked seasonal variations. Clinical evaluation arrived at a similar prevalence rate of SAD as the questionnaire.

Treatment of seasonal affective disorder: a review

OBJECTIVE

To review the status of current treatment of seasonal affective disorder (SAD).

METHOD

Treatment studies of SAD published between January 1989 and March 1995 were identified using a computerized MEDLINE literature search. Additional citations were obtained from the reference sections of these articles. Studies included in this review were selected using operational methodologic criteria.

RESULTS

Many studies support the efficacy of bright light therapy using a fluorescent light box. The best studied protocol is > 2500 lux white light for 2 hours per day, but newer protocols using 10,000 lux for 30 minutes have comparable response rates. Studies of light visors and other head-mounted devices also report similar response rates, but have not yet shown superiority over putative control conditions. There are fewer medication studies in SAD, but controlled studies suggest that fluoxetine, d-fenfluramine and propranolol are effective. Other treatments such as dawn simulation require further study. No studies of psychological treatments for SAD were found. Many studies had methodologic limitations, including brief treatment periods, small sample sizes, and lack of replication, that limit the generalizability of findings.

CONCLUSION

There are several well-studied, effective treatments for SAD, including light therapy and medications. However, further research must be done to demonstrate sustained treatment response over time, to clarify the intensity-response relationship of light therapy, to clarify the role of light therapy and medications, and to assess combination treatments.

Personality disorders in patients with winter depression

Sixty-six patients satisfying the criteria for seasonal affective disorder (SAD) winter depression type (n = 57) or subsyndromal SAD (n = 9), were interviewed in a nondepressed state with the Structured Interview for DSM-III-R Personality Disorders (SIDP-R). Twenty-three percent of the patients in the SAD sample met DSM-III-R criteria for one or more categorical diagnosis of personality disorder (PD). Disorders in cluster C occurred in 18% of the sample, while 12% had cluster B PDs and 5% a cluster A disorder. The relative number of positive criteria, as a dimensional measure of PD, were higher for all cluster C disorders than for any PD in the other clusters. Our data indicate that the pattern of personality disorders in patients with winter SAD are similar to that previously reported for outpatients with non-SAD major depression. We explored the relationship between lifetime severity and clinical manifestation of SAD and dimensional measures of PD with multiple regression analyses. No significant association was found. This is in accordance with the hypothesis that the two disorders are distinct conditions with independent causes.

Mood and behavioral effects of four-week light treatment in winter depressives and controls

This study investigated (1) the time-course and durability of antidepressant effects of bright light in winter depressives, and (2) the effects of bright light on mood and behavior in normal controls in a 4-week open treatment paradigm. Twelve subjects in a major depressive episode during recurrent major depressive or bipolar disorder with seasonal pattern and 12 control subjects received 2,500 lux light between 0600 and 0800 hours, while 12 controls arose at 0600 hours for quiet activities without exposure to bright light. In depressives, maximal decrements in depression ratings were not reached until the fourth week of treatment. Four depressives experienced clinically significant hypomanic symptoms. Controls treated with light demonstrated significantly higher clinician ratings of hypomanic symptoms than no-light controls. When depressives and controls were combined, seasonality, but not diagnosis, predicted the emergence of manic-like symptoms. Implications for bright light treatment in the clinical setting are discussed.

Thyroid function before and after four-week light treatment in winter depressives and controls

Thyroid function in patients in a current major depressive episode during the course of recurrent major mood disorder with seasonal pattern according to DSM-IIIR was compared to that of controls before and after 4 weeks' light treatment, and to that of controls at baseline and after 4 weeks' of arising early without exposure to bright light. No consistent abnormalities in thyroxine, free thyroxine index, triiodothyronine, reverse triiodothyronine, thyrotropin, thyrotropin response to TRH infusion, or thyroid autoantibodies were seen in depressives at baseline. No differences in these parameters were seen at baseline between depressives and controls. No intergroup differences were seen with treatment, although reverse T3 decreased significantly during the protocol in all groups. These data do not support the hypothesis that the thyroid axis plays a role in the pathogenesis of winter depressive symptoms or their response to light treatment.