Immune-inflammatory markers in patients with seasonal affective disorder: effects of light therapy

BACKGROUND: There is increasing evidence that an activation of the immune-inflammatory system is involved in the pathophysiology of depressive disorders. The purposes of this study were to (1) compare immune-inflammatory markers in patients with seasonal affective disorder (SAD) with those in matched normal controls; and (2) examine the effects of light therapy on the immune-inflammatory markers in patients with SAD. METHODS: Plasma concentrations of interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R) and soluble IL-2 receptor (sIL-2R) were measured in 15 patients with SAD and 15 age- and sex-matched normal controls. Of the 15 patients, 14 had repeated blood sampling for these variables following 2 weeks of light therapy. RESULTS: We found that patients with SAD had significantly increased IL-6 levels compared to normal controls (P<0.0005). There was a trend toward increased sIL-2R in patients with SAD (P=0.09). There was no significant difference in sIL-6R level between the two diagnostic groups (P=0.18), but the product term (IL-6xsIL-6R) was significantly higher in patients with SAD than that in normal control controls (P<0.0003). Furthermore, all 14 patients who completed the study improved with 2 weeks of light therapy and nine of them (64%) had 50% reduction in score of the Hamilton Depression Rating Scale-SAD version post-treatment compared to baseline. However, the initially increased immune markers in SAD patients were not significantly altered by the therapeutic light therapy. LIMITATIONS:This study was limited to a small sample size and other immune inflammatory markers should be measured for further evidence of immune activation in seasonal depression. CONCLUSIONS: Our results of increased IL-6, IL-6xsIL-6R, and sIL-2R in patients with SAD suggest an activation of the immune-inflammatory system in winter depression, which is not altered by 2 weeks of successful light therapy.     

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.     

A comparison of open treatment of seasonal major and minor depression with light therapy

BACKGROUND: Although several investigators have described a milder form of seasonal affective disorder (SAD), called subsyndromal SAD, little is known about the effect of light therapy in this group. The current study evaluates 3 weeks of open treatment with light therapy in SAD and subsyndromal SAD patients. METHODS: Subjects with major or minor depression according to DSM-IV with a seasonal pattern were recruited during the winter of 1998-1999 from clinic patients and media advertising. Subjects were commenced on open treatment of morning light therapy, for 30 min daily using a new fluorescent light therapy unit that produced approximately 5,000 lux at a distance of 12 inches. The treatment lasted 3 weeks and at the end of the first and second week of treatment the duration of exposure could be increased to a maximum of 60 min at the discretion of the clinician. The Structured Interview Guide for the Hamilton Depression Rating Scale-SAD version (SIGH-SAD) was administered weekly to evaluate outcome. Response was defined in a variety of ways to reflect the fact that subsyndromal SAD subjects had milder symptoms. RESULTS: Forty-six subjects entered treatment and 44 (SAD, n = 29, subsyndromal SAD, n = 15) completed at least 2 weeks. Response rates were generally similar in SAD subjects (64-69%) and subsyndromal SAD (40-67%) patients. There was a trend for longer exposure to be associated with better outcome. CONCLUSIONS: Light therapy may be an effective treatment for subjects with both major and minor depression with a seasonal pattern. Optimal duration, for the light therapy unit used in this study, is likely 45-60 min daily.     

Cognitive-behavioral therapy, light therapy, and their combination in treating seasonal affective disorder

Background: The need to develop supplementary or alternative treatments for seasonal affective disorder (SAD) is underscored by the significant minority (47%) of SAD patients that is refractory to light therapy, the persistence of residual symptoms despite light treatment, and poor long-term compliance with light use. Because preliminary studies suggest that cognitive and behavioral factors are involved in SAD, cognitive-behavioral therapy (CBT) warrants investigation as a possible treatment option. Methods: We piloted a 6-week randomized clinical trial to compare a standard light therapy protocol; a novel, SAD-tailored, group CBT intervention; and their combination in ameliorating and remitting a current SAD episode and as prophylaxis against episode recurrence. Depressive symptom severity and remission rates were assessed at post-treatment and at a 1-year follow-up visit to examine long-term treatment durability. Results: CBT, light therapy, and their combination all demonstrated significant reductions in depressive symptoms on two different outcome measures. Remission rates varied by measure, but did not reach statistical significance. During the subsequent winter, CBT, particularly in combination with light therapy, appeared to improve long-term outcome regarding symptom severity, remission rates, and relapse rates. No CBT-treated participant, with or without light, experienced a full SAD relapse compared to over 60% of those treated with light alone. Limitations: These results should be viewed as preliminary and are limited by the small sample size (n=23) and lack of a control group. Conclusions: The nearly half of SAD patients who do not remit with light alone may benefit from CBT as an adjunct or alternative treatment, especially as a prophylaxis against episode recurrence.     

Cognitive characteristics of seasonal affective disorder: A preliminary investigation

Light therapy, the current treatment for Seasonal Affective Disorder (SAD), does not help everyone suffering from SAD. This paper examines whether patients with SAD potentially might benefit from cognitive behaviour therapy by investigating whether they show a similar cognitive profile to those with non-seasonal depression for whom cognitive therapy has been shown to be effective. Ten subjects with SAD were compared to 11 non-seasonally depressed and 10 normal controls on a range of measures including the Automatic Thoughts Questionnaire and the Dysfunctional Assumptions Scale. One-way analysis of variance showed that the SAD group reported significantly more negative automatic thoughts and dysfunctional attitudes than a non-depressed control group but did not differ from a group with non-seasonal depression. The results suggest that patients with SAD may respond to cognitive behaviour therapy like those with non-seasonal depression. Further research is therefore recommended to examine the efficacy of cognitive therapy as a complementary addition to light therapy in the treatment of SAD and to examine other cognitive aspects of SAD.     

Five-factor personality traits in patients with seasonal depression: treatment effects and comparisons with bipolar patients.

BACKGROUND: Increasingly, the Five Factor Model (FFM) of personality is being used to assess personality characteristics of patients with Axis I disorders. Recent study indicates that patients with the seasonal subtype of major depression (SAD) may differ meaningfully from other depressed patients. In the present study, we further examined this finding, with attention to the stability of personality characteristics across treatment. METHODS: We used the NEO-FFM to assess the personality characteristics of two samples of depressed outpatients: patients with SAD and patients with bipolar disorder. Assessment was repeated in the SAD patients after light therapy. RESULTS: Consistent with previous research, we found elevated scores on the Openness domain in the SAD patients. SAD patients also scored significantly lower on Neuroticism and significantly higher on the Conscientiousness and Extroversion domains than patients with bipolar disorder. Scores on the Openness domain remained elevated after treatment of SAD; this occurred in the context of significant decreases in Neuroticism and increases in Extroversion scores. LIMITATIONS: These results were obtained in a relatively small-sample study. Although our sample of bipolar patients were taking mood stabilizers, it is unlikely that medication effects could explain our results. CONCLUSIONS: Our findings are consistent with those reported by Bagby et al. (Major depression and the five-factor model of personality. J. Pers. Disord. 1995;9:224-234) and suggests that Neuroticism and Extroversion are the FFM domains most responsive to treatment for depression. Our results also suggest that elevations on the Openness domain do not change with treatment and may be an enduring characteristic of patients with SAD.     

The relationship of affective state to dietary preference: winter depression and light therapy as a model

Seasonal affective disorder (SAD) patients often crave carbohydrates when depressed during the winter. We measured dietary intake using a daily Food/Drink Frequency Questionnaire in 36 SAD patients over four conditions: when depressed in winter, during light therapy (1 h 2500 lux, morning or evening), during withdrawal, and when euthymic in summer. Carbohydrate intake (both sweet and starch) in the second half of the day was elevated during winter depression and was as low after light therapy as in summer. The medial hypothalamus is hypothesised to play a key role in coupling 'mood and food' in SAD.     

Light room therapy effective in mild forms of seasonal affective disorder--a randomised controlled study

BACKGROUND: The most common way to provide bright light therapy to Swedish patients with Seasonal Affective Disorder (SAD), is treatment in a light therapy room. Since few studies have evaluated treatment provided in this setting and few have evaluated the effect of bright light in sub-clinical SAD (S-SAD), such a study including a one-month follow-up was designed. METHODS: Fifty adults recruited from a previous prevalence study and clinically assessed as having SAD or S-SAD, were randomised to treatment in a light room or to a three-week waiting-list control group. The Hamilton Depression Rating Scale-Seasonal Affective Disorders Self-rating 29-items Version (SIGH-SAD/SR) was used to measure depressive mood at baseline, directly following treatment and at the one-month follow-up. RESULTS: ANCOVA with adjustment for baseline depression score, showed a significant main effect for the light room therapy group (p<0.001). Fifty-four percent (n=13/24) improved > or = 50% while no such improvement was seen in the control condition (n=0/24). After merging the two groups, repeated measures ANOVA confirmed the experimental analysis (p<0.001). At the one-month follow-up, 83.0% (n=39/47) had improved > or = 50% and 63.8% (n=30/47) had normal depression scores, i.e. < or = 8. CONCLUSIONS: Light room therapy was effective in reducing depressive symptoms in subjects with winter depressive mood. Results were maintained over a period of one month.     

Winter and summer outdoor light exposure in women with and without seasonal affective disorder

BACKGROUND: The annual decrease of daylight duration initiates a depressive phase in patients with seasonal affective disorder (SAD), and light therapy treats it. How much bright light exposure in winter and summer these patients actually receive may help understand the pathogenetic factors initiating SAD. METHODS: During a week in winter and summer, women with and without SAD kept daily logs of the time spent outdoors, subjective sleep, and self-ratings of mood and alertness. RESULTS: Compared with the winter depressive state, mood, alertness, and sleep of SAD patients improved in summer to control values, but did not correlate with the amount of light exposure. In summer, patients with SAD spent more time outdoors than controls. LIMITATION: Light logs--in comparison with light monitor measurements--may overestimate light exposure outdoors. CONCLUSION: Women with SAD do not spend less time outdoors in winter than controls, but spend more time outdoors in summer. CLINICAL RELEVANCE: Patients with SAD show a high amplitude seasonal difference in outdoor light exposure. The susceptibility to winter depression may arise not from behaviourally-related lack of sufficient light exposure, but an increased vulnerability to the amount of light received. They may require more light than controls to remain euthymic (higher light exposure in summer, light therapy in winter).     

Seasonality in major depressed inpatients

The proportion of patients with a fall-winter pattern of feeling worst comparable to that of patients with seasonal affective disorder (SAD) was 11.4% in our sample of major depressed inpatients. Since admission to psychiatric inpatient services is influenced to an unknown extent by various factors it is not possible to generalize our data to other facilities. However, based on the results of our study it seems worth while to screen depressed patients for their degree of seasonality since treatment with bright artificial light has been shown to be beneficial in SAD patients and its subsyndromal form.     

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.     

The effects of ultraviolet-A wavelengths in light therapy for seasonal depression.

Although light therapy is a recognized effective treatment for seasonal affective disorder (SAD), there has been little research into the critical wavelengths of light that produce the antidepressant effect. Previous studies found conflicting results for the importance of the ultraviolet (UV) spectrum in the therapeutic effect of light therapy. To assess the clinical effects of UV-A wavelengths (315-400 nm), we studied 33 depressed SAD patients diagnosed with structured interviews by DSM-IIIR criteria. Following a baseline week, patients underwent 2 weeks of 2500 lux light therapy for 2 h daily (06:00-08:00). Light therapy consisted of cool-white fluorescent light with the addition of a special UV-A fluorescent tube. Patients were randomized to wear glasses during light therapy that either blocked (UV-blocked condition) or passed (UV-A condition) wavelengths below 400 nm. Both treatments significantly reduced all depression ratings, but no differences were found between the UV-A and UV-blocked conditions. We conclude that the UV-A spectrum does not increase the antidepressant response of light therapy. Given the potential side effects of chronic UV exposure, clinical application of light therapy should use light sources that have the UV spectrum filtered.     

Effects of rapid tryptophan depletion in patients with seasonal affective disorder in natural summer remission

BACKGROUND: Serotonergic mechanisms have been proposed for the pathophysiology of seasonal affective disorder (SAD) and the therapeutic effect of bright-light treatment. Previously, we showed that SAD patients, in clinical remission with light therapy during the winter, experienced transient depressive relapses after a rapid tryptophan depletion (RTD) technique, which results in decreased brain serotonin levels. The objective of this study was to investigate the effect of RTD in SAD patients who were in natural summer remission. METHODS: Twelve drug-free patients with SAD by DSM-IV criteria and 10 normal subjects participated in this double-blind, placebo-controlled, crossover study. SAD patients were in natural summer remission for at least 8 weeks. Behavioural ratings and plasma tryptophan levels were obtained before, and 5 h after, ingesting an amino acid (AA) mixture +/- tryptophan. Experimental RTD and control sessions were scheduled 1 week apart. RESULTS: The RTD session resulted in significant reduction in total and free plasma tryptophan levels compared to the control session. The behavioural data were analysed using repeated measures analysis of variance. This analysis found significant main effects of time (higher scores after AA ingestion) and diagnosis (higher scores in SAD patients), but no main effect of session or significant interaction effects between the three factors. Thus, there were no significant behavioural effects of RTD compared to the sham depletion control session. CONCLUSIONS: The summer remission experienced by SAD patients is not dependent on plasma tryptophan levels (and presumably brain serotonin function) in the same manner as that of remission after light therapy. These results conflict with those of other laboratories, perhaps because of differences in study samples.     

Mood-worsening with high-pollen-counts and seasonality: a preliminary report

BACKGROUND: Because aeroallergens produce inflammation in the respiratory airways, and inflammation triggers depression in vulnerable individuals, we hypothesized that mood sensitivity to pollen, the most seasonal aeroallergen, will be associated with a greater seasonality of mood. Since pollen is absent during winter, we specifically predicted that mood sensitivity to tree pollen will predict non-winter SAD but not winter SAD. METHODS: A convenience sample of African and African American college students who lived in the Washington DC metropolitan area for at least the past 3 years completed the Seasonal Pattern Assessment Questionnaire (SPAQ), from which the Global Seasonality Score (GSS) was calculated, a diagnosis of cumulative SAD (syndromal or subsyndromal SAD) was derived, a seasonal pattern (winter vs non-winter) identified, and self-reported mood changes during high pollen counts obtained. A Mann-Whitney test was used to compare GSS between participants with vs without mood worsening during high pollen counts. The capability of mood worsening with high pollen counts, gender, ethnicity, and age to predict non-winter SAD was analyzed with logistic regressions. RESULTS: GSS was greater (z=5.232, p<0.001) in those who reported mood worsening with high pollen counts. Mood sensitivity to pollen predicted non-winter SAD (p=0.017), but not winter SAD. LIMITATIONS: The SPAQ is not a definitive tool to assess seasonality, and self-reported mood worsening with high pollen counts relies on recollection. No direct measures of depression scores or pollen counts were collected. The non-winter SAD concept has not been previously established. CONCLUSIONS: Our study, which should be considered preliminary in light of its limitations, suggests that self-reported mood-worsening with high pollen count is associated with a greater seasonality of mood, and predicts SAD of non-winter type.     

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.     

Prevalence of premenstrual dysphoric disorder in female patients with seasonal affective disorder

BACKGROUND: Both seasonal affective disorder/winter type (SAD) and premenstrual dysphoric disorder (PMDD) are cyclical disorders characterized by so-called atypical depressive symptoms. In the present study we compared the point prevalence rates of PMDD between a sample of premenopausal female patients suffering from SAD and healthy female controls. METHODS: Forty-six female patients with SAD and 46 healthy controls were included in our study. All subjects underwent a semistructured clinical interview according to DSM IV criteria and completed the Seasonal Pattern Assessment Questionnaire. PMDD was diagnosed in a self-rating interview for PMDD according to DSM IV criteria. To verify the diagnosis of PMDD, all patients were followed up in stable summer remission using daily self-rating scales for two full menstrual cycles. RESULTS: Patients with SAD fulfilled significantly more often the diagnostic criteria for PMDD than female healthy controls (46% vs. 2%, respectively; chi-square: P<0.001). CONCLUSIONS: These results provide preliminary evidence for a high point prevalence rate of PMDD in premenopausal females with SAD. CLINICAL IMPLICATIONS: It would be worthwhile to investigate whether an additional diagnosis of PMDD has an impact on the clinical outcome and the response to bright light therapy in female patients with SAD.     

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.     

Monorhinal odor identification and depression scores in patients with seasonal affective disorder

BACKGROUND: Visual and olfactory pathways are interconnected. Olfactory deafferentation unmasks photoperiodic responsiveness in some nonphotoperiodic animals such as laboratory rats. By analogy, we hypothesized that olfactory deficits may unmask seasonal rhythms in certain individuals, namely those with seasonal affective disorder (SAD). Since previous studies suggest lateralized hemispheric dysfunction in SAD, and since olfactory neurons' primary projections are largely ipsilateral, we assessed olfactory identification performance on both the right and left side of the nose. METHODS: Twenty-four patients with SAD and 24 matched controls were studied using a phenyl ethyl alcohol detection threshold test bilaterally and the University of Pennsylvania Smell Identification Test unilaterally. Subjects rated their mood using the Self Assessment Mood Scale for SAD. Patients' testing was done in both 'depressed' and 'improved on light' states. RESULTS: No difference in olfactory performance was found between patients and controls or between patients before and after light treatment. However, right-side identification scores were negatively correlated with 'typical' depression scores (r = -0.56, P = 0.006), while left-side olfactory scores were not. Atypical depression scores were unrelated to olfactory performance. Similar correlations emerged between the olfactory identification laterality quotient (Right - Left)/(Right + Left) and typical depressive scores (r = - 0.64, P < 0.001) and total depression scores (r = - 0.59, P < 0.004). LIMITATIONS: We studied a demographically heterogeneous sample and did not control for menstrual factors. DISCUSSION: Our results add to previous evidence of lateralized hemispheric involvement in SAD and suggest that olfaction may be related to seasonal emotional rhythms in humans.     

Seasonal and nonseasonal depression: how do they differ? Symptom profile,clinical and family history in a general population sample

BACKGROUND: A small number of studies have previously compared the symptom profiles and clinical and family history patterns of patients with seasonal and nonseasonal depression. However, previous research has tended to be conducted in secondary and tertiary care populations. Little comparative data is available for seasonal and nonseasonal depression in general population samples. METHODS: Patients aged 18-64 registered on a primary care database in North Wales were screened via post for the presence of SAD via the Seasonal Patterns Assessment Questionnaire (SPAQ) and depression via the Beck Depression Inventory (BDI). Interview-confirmed cases of SAD (n=25) and major depression (n=43) were compared in terms of symptom profile, clinical history and family history of psychiatric disorder. RESULTS: Seasonal depression was found to be associated with lower occupational and cognitive impairment and psychiatric intervention than nonseasonal depression. The symptoms of hopelessness and weight loss were particularly predictive for nonseasonal depression. LIMITATIONS: The study was conducted at only one geography. CLINICAL RELEVANCE: Seasonal depression's discrete symptom profile may be used to distinguish cases of seasonal and nonseasonal depression in primary care patients. CONCLUSIONS: SAD appears to be a relatively mild variant of depression, but this finding should not detract from the need for improved identification and treatment of SAD in primary care populations.     

Sleep deprivation as a predictor of response to light therapy in major depression

BACKGROUND: While the majority of depressed patients benefit from total sleep deprivation (TSD), light therapy is regarded as a first-line treatment only for seasonal affective disorder (SAD). The results of light therapy in nonseasonal major depressive disorder have been non-conclusive. We examined the correlation of TSD response and light therapy response in major depressed patients. METHODS: 40 inpatients with major depressive disorder (seven with seasonal pattern, 33 without seasonal pattern) were deprived of a night's sleep. The TSD responders, as well as the TSD nonresponders, were randomly assigned to receive adjunct light therapy either with bright white light (2500 lux) or dim red light (50 lux) during 2 weeks beginning on the third day after TSD. RESULTS: The 20 TSD responders improved significantly better under the light therapy than the 20 TSD nonresponders (according to the Hamilton Depression Rating Scale and the self-rating depression scale Bf-S; v. Zerssen). LIMITATIONS: No significant difference could be found between the two light intensities. Since the patients were additionally treated with medication an interaction with the two adjunctive therapies cannot be excluded. CONCLUSION: Our results indicate that a positive TSD response in major depressed patients can be predicative of beneficial outcome of subsequent light therapy.