Seasonal affective disorder among primary care consulters in January: prevalence and month by month consultation patterns

Frequency and characteristics of individuals with seasonal pattern among depressive patients attending primary care in France

OBJECTIVE

High rates of bipolar disorder (BD) have been found among major depressives with seasonal pattern (SP) consulting in psychiatric departments, as well as among patients seeking primary care. As SP was reported to be common in the latter, the current study was designed to assess (a) the frequency and characteristics of SP among major depressives attending primary care and (b) the prevalence and aspects of BD in this population.

METHODS

Among 400 patients who consulted French general practitioners (GPs) for major depression between February and December 2010, 390 could be included in the study: 167 (42.8%) met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for seasonal pattern [SP(+)], whereas 223 (57.2%) did not meet these criteria [SP(-)]. The two groups were compared on demographic, clinical, family history and temperamental characteristics.

RESULTS

Compared to SP(-), SP(+) patients were more frequently female, married and with a later age at first depressive episode, and showed more atypical vegetative symptoms, comorbid bulimia and stimulant abuse. They also exhibited more lifetime depressive episodes, were more often diagnosed as having BD II and met more often bipolarity specifier criteria, with higher rates of bipolar temperaments and a higher BD family loading. Among SP(+) patients, 68.9% met the bipolarity specifier criteria, whereas 31.1% did not. Seasonality was not influenced by climatic conditions. The following independent variables were associated with SP: BD according to bipolarity specifier, female gender, comorbid bulimia nervosa, hypersomnia, number of depressive episodes and family history of substance abuse.

CONCLUSIONS

Seasonal pattern is frequent among depressive patients attending primary care in France and may be indicative of hidden bipolarity. Given the risks associated with both SP and bipolarity, GPs are likely to have a major role in regard to prevention.

Direct health care costs of treating seasonal affective disorder: a comparison of light therapy and fluoxetine

Objective. To compare the direct mental health care costs between individuals with Seasonal Affective Disorder randomized to either fluoxetine or light therapy. Methods. Data from the CANSAD study was used. CANSAD was an 8-week multicentre double-blind study that randomized participants to receive either light therapy plus placebo capsules or placebo light therapy plus fluoxetine. Participants were aged 18-65 who met criteria for major depressive episodes with a seasonal (winter) pattern. Mental health care service use was collected for each subject for 4 weeks prior to the start of treatment and for 4 weeks prior to the end of treatment. All direct mental health care services costs were analysed, including inpatient and outpatient services, investigations, and medications. Results. The difference in mental health costs was significantly higher after treatment for the light therapy group compared to the medication group-a difference of $111.25 (z = -3.77, P = 0.000). However, when the amortized cost of the light box was taken into the account, the groups were switched with the fluoxetine group incurring greater direct care costs-a difference of $75.41 (z = -2.635, P = 0.008). Conclusion. The results suggest that individuals treated with medication had significantly less mental health care cost after-treatment compared to those treated with light therapy.

Seasonal severity of depressive symptoms as a predictor of health service use in a community-based sample

OBJECTIVE

To determine whether severity of seasonal depressive symptoms is an independent predictor of depression-specific health service use.

METHODS

Cross-sectional telephone survey evaluating mood-related symptom changes across seasons using a structured interview based on the World Mental Health Composite International Diagnostic Interview, in a community sample representative of the province of Ontario, Canada (N = 1605). This study focuses on the 625 individuals (out of a total of 1605 interviewed) who screened positive for lifetime depressive symptoms. Severity of seasonal symptoms of depression (or "seasonality") was measured using the Seasonal Depression Severity (SDS) score (range 0-36). The primary outcome was lifetime depression-specific use of health services from a physician (family physician or psychiatrist). Lifetime psychotropic medication use, use of health services from a non-physician therapist, and psychiatric hospitalization were secondary outcomes. Other important variables that are known to predict depression-specific health service use were considered in multivariable analysis.

RESULTS

In our sample of individuals with depressive symptoms, those who had used physician health services had higher SDS scores than non-users (11.5 (SD 7.2) vs. 9.7 (SD 6.4), t(616) = 3.182, P = 0.001). In multivariable analysis, SDS score was independently associated with depression-specific health service use by a physician (OR = 1.04, 95% CI 1.01-1.07, p = 0.004). The relationship between seasonality and use of psychotropic medication use was similar (OR = 1.04, 95% CI 1.01-1.07, p = 0.007).

CONCLUSIONS

Seasonality was independently associated with depression-specific health service use for individuals with depressive symptoms. The results imply that greater seasonality may independently reflect increased severity and need for treatment of depression.

An overview of seasonal affective disorder and its treatment options

Seasonal affective disorder (SAD) is defined as a history of major depressive episodes that recur regularly at a particular time of year. Depending on the diagnostic instruments and criteria available, the reported prevalence (1%-10%) varies. Neurotransmitter abnormalities have been implicated in the pathophysiology, but they do not necessarily explain the seasonal pattern or the known chronobiological abnormalities in SAD compared with nonseasonal depression. Circadian rhythm abnormalies have been hypothesized to account for these aspects of SAD, and they provide a rationale for the therapeutic use of light therapy. Family history, twin, and molecular genetics studies suggest that hereditary factors are also involved. Light therapy and antidepressant medication are effective treatment options, with limited evidence for the efficacy of psychotherapy. Some studies demonstrate that narrow-band short wavelength "blue" light, naturalistic dawn simulation, and high-density negative air ionization are effective. Patients should be informed of the benefits of diet and exercise. Light therapy should be clinically monitored in the same manner, as it is done for other antidepressant treatments.

High prevalence of self-reported winter depression in a Swedish county

The prevalence of winter depression was unknown in Sweden, therefore prevalence figures of seasonal affective disorder (SAD) and subsyndromal SAD (S-SAD) were estimated. Age and gender differences, prevalence in the group of non-responders and some psychometric qualities of the Seasonal Pattern Assessment Questionnaire (SPAQ) were calculated. A modified version of the SPAQ was sent to a random sample of 2500 persons (response rate 66.3%, n=1657) between 18 and 64 years residing in Dalarna, a county in central Sweden. The sample was proportionally stratified according to age, gender and home municipality. The prevalence of winter SAD was estimated at 8% and S-SAD at 10.8%. It was approximately twice as common among women and younger persons. A total of 3.1% reported seasonal problems to be severe or disabling and 19.3% that everyday life was negatively affected. Experiencing seasonally changing depressive symptoms was common in the population. Factor analysis of the Global Seasonal Score resulted in one factor and the internal consistency was 0.88 (Cronbach's alpha). The results indicate that self-reported recurrent depression during winter is common in Sweden and should therefore receive more attention from health care authorities.

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.

Mood and behaviour problems associated with seasonal changes in Britain and Ireland

BACKGROUND

Research from across the world has shown that rates of seasonal mood disturbances may vary according to such factors as geographical location, age and gender. Little is known of the nature of these problems within representative community samples in UK and Ireland.

AIMS

In two studies we examined the extent to which winter disrupts mood and behaviour among random samples of British and Irish adults.

METHODS

In the first study, 533 adults randomly chosen from electoral data from four towns spread across 50-58 degrees N completed the Seasonal Pattern Assessment Questionnaire (SPAQ). In the second study, 498 adults from two towns in Northern Ireland (54 degrees N) completed the SPAQ.

RESULTS

Although the combined response rate across the two studies was low (20.5%), the prevalence rates were similar to several other western European sites. The rate of SAD and S-SAD averaged across the six centres as determined from strict SPAQ criteria, was 6.7% and 10.5% respectively. There was some variability in rates from town to town, with one Northern Irish town presenting rates more associated with areas at much lower latitudes, although most differences between towns were not significant. As in most other studies, females of reproductive age tended to supply the higher number of incidences.

CONCLUSION

This report from community samples across six sites confirms earlier suggestions that rates of seasonal disturbance in mood and behaviour deserve serious consideration by mental health practitioners throughout the region.

Use of health care services in seasonal affective disorder

BACKGROUND

Little is known about the presentation and management of seasonal affective disorder (SAD) in primary care.

AIMS

To determine the use of health care services by people suffering from SAD.

METHOD

Following a screening of patients consulting in primary care, 123 were identified as suffering from SAD. Each was age- and gender-matched with two primary care consulters with minimal seasonal morbidity, yielding 246 non-seasonal controls. From primary care records, health care usage over a 5-year period was established.

RESULTS

Patients with SAD consulted in primary care significantly more often than controls and presented with a wider variety of symptoms. They received more prescriptions, underwent more investigations and had more referrals to secondary care.

CONCLUSIONS

Patients with SAD are heavy users of health care services. This may reflect the condition itself, its comorbidity or factors related to the personality or help-seeking behaviour of sufferers.

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.

Seasonal affective disorders: relevance of Icelandic and Icelandic-Canadian evidence to etiologic hypotheses

OBJECTIVE

This study tests the suggestion of earlier studies concerning the importance of genetic factors in the etiology of winter seasonal affective disorders (SADs) and subsyndromal winter SAD (S-SAD).

METHOD

Two study populations of Winnipeg, Manitoba residents were canvassed: 250 adults of wholly Icelandic descent and 1000 adults of non-Icelandic descent. We distributed the Seasonal Pattern Assessment Questionnaire by mail to these 2 populations, yielding 204 and 449 valid responses, respectively.

RESULTS

Rates of SAD and S-SAD proved markedly lower in the Icelandic population than those in the non-Icelandic population.

CONCLUSIONS

These differences seem unexplained by differences in ambient light or climate, thus indicating that genetic factors contribute to the expression of SADs. Compared with earlier findings from a group of adults of wholly Icelandic descent living in nearby rural Manitoba, the etiologic importance of as-yet-undetermined environmental factors unrelated to latitude or ambient light is also indicated.

Seasonal affective disorder: prevalence, detection and current treatment in North Wales

BACKGROUND

There is a paucity of information concerning the prevalence and detection of seasonal affective disorder (SAD) in UK populations.

AIMS

To determine the prevalence, detection and current treatment of SAD within a general population sample.

METHOD

The study was conducted in conjunction with the Outcomes of Depression International Network (ODIN) project, a large European study of depression. At the North Wales arm of the project, 1999 adults were randomly selected from a health authority database and screened by post for SAD with the Seasonal Patterns Assessment Questionnaire (SPAQ). Those scoring above cut-off were offered diagnostic interview, after which diagnosis of SAD according to DSM-IV criteria could be made.

RESULTS

The prevalence rate of SAD was calculated to be 2.4% (95% CII.4-1.3). The majority of identified cases had not previously received a diagnosis of SAD from their general practitioner, although over half had been diagnosed with other forms of depression and had been prescribed antidepressant medication.

CONCLUSIONS

Although SAD was found to be common in this general population sample it appeared to be largely underdiagnosed and/or misdiagnosed.

Light therapy for seasonal affective disorder in primary care: randomised controlled trial

BACKGROUND

Studies of light therapy have not been conducted previously in primary care.

AIMS

To evaluate light therapy in primary care.

METHOD

Fifty-seven participants with seasonal affective disorder were randomly allocated to 4 weeks of bright white or dim red light. Baseline expectations for treatment were assessed. Outcome was assessed with the Structured Interview Guide for the Hamilton Depression Scale, Seasonal Affective Disorder Version.

RESULTS

Both groups showed decreases in symptom scores of more than 40%. There were no differences in proportions of responders in either group, regardless of the remission criteria applied, with around 60% (74% white light, 57% red light) meeting broad criteria for response and 31% (30% white light, 33% red light) meeting strict criteria. There were no differences in treatment expectations.

CONCLUSIONS

Primary care patients with seasonal affective disorder improve after light therapy, but bright white light is not associated with greater improvements.

Estimated prevalence of the seasonal subtype of major depression in a Canadian community sample

OBJECTIVE

To examine estimates of lifetime prevalence of seasonal affective disorder (SAD) in Toronto, Ontario.

METHOD

Random telephone numbers were generated for the city of Toronto, and 781 respondents completed a telephone interview. Trained nonphysician interviewers conducted all interviews, which involved structured questions for diagnosing major depression. Patterns of symptom change across seasons were evaluated to establish a diagnosis of SAD according to DSM-III-R criteria.

RESULTS

Correcting for sex and age, the prevalence of SAD defined by DSM-III-R criteria was 2.9% (95% CI, 1.7% to 4.0%), and the overall lifetime prevalence of major depression in the sample was 26.4% (95% CI, 23.3% to 29.4%). Some subjects were contacted for a follow-up interview conducted in person; the positive predictive value for the diagnosis of major depression for the telephone interview was 100%, and the negative predictive value was 93%.

CONCLUSIONS

The seasonal subtype of depression represents 11% of all subjects with major depression, suggesting that SAD is a significant public health concern. The telephone interview demonstrated adequate reliability, indicating that it is appropriate for epidemiological surveys of this nature.

Seasonal affective disorder among primary care attenders and a community sample in Aberdeen

BACKGROUND

There are no large published studies of the prevalence of seasonal affective disorder (SAD) among UK populations.

AIM

To determine the prevalence of SAD among patients attending a general practitioner (GP).

METHOD

Patients aged 16-64 consulting their GPs in Aberdeen during January were screened with the Seasonal Pattern Assessment Questionnaire (SPAQ). SPAQs were also mailed to 600 matched patients, who had not consulted their GP during January. Surgery attenders who fulfilled SPAQ criteria for SAD were invited for interview to determine whether they met criteria for SAD in DSM-IV and the Structured Interview Guide for the Hamilton Rating Scale for Depression--Seasonal Affective Disorder Version (SIGH-SAD).

RESULTS

Of 6161 surgery attenders, 4557 (74%) completed a SPAQ; 442 (9.7%) were SPAQ cases of SAD. Rate of caseness on the SPAQ did not differ between surgery attenders and non-attenders. Of 223 interviewed SPAQ cases of SAD, 91 (41%) also fulfilled DSM-IV and SIGH-SAD criteria.

CONCLUSIONS

There is a high prevalence of SAD among patients attending their GPs in January in Aberdeen; this is likely to reflect a similar rate in the community.

Seasonal affective disorder

Seasonal affective disorder (SAD) is a form of recurrent depressive or bipolar disorder, with episodes that vary in severity. Seasonal patterns of depressive episodes are common, but SAD seems to be less common than such patterns suggest. SAD was at first believed to be related to abnormal melatonin metabolism, but later findings did not support this hypothesis. Studies of brain serotonin function support the hypothesis of disturbed activity. The short-allele polymorphism for serotonin transporter is more common in patients with SAD than in healthy people. Atypical depressive symptoms commonly precede impaired functioning, and somatic symptoms are frequently the presenting complaint at visits to family physicians. The best treatment regimens include 2500 Ix of artificial light exposure in the morning. When patients seem to have no response or to prefer another treatment, antidepressants should be considered.