Antoinette L. Bouhuys

Seasonal affective disorder and latitude: a review of the literature.

BACKGROUND The aim of the study is to investigate the relationship between the prevalence of SAD and latitude. METHODS An overview of the epidemiological literature on the prevalence of SAD is given and studies relevant for the latitudinal dependency of prevalence will be analyzed and discussed. RESULTS The mean prevalence of SAD is two times higher in North America compared to Europe. Over all prevalence studies, the correlation between prevalence and latitude was not significant. A significant positive correlation was found between prevalence and latitude in North America. For Europe there was a trend in the same direction. CONCLUSIONS The influence of latitude on prevalence seems to be small and other factors like climate, genetic vulnerability and social-cultural context can be expected to play a more important role. Additional controlled studies taking these factors into account are necessary to identify their influence.

Depression in later life: three etiologically different subgroups

BACKGROUND Various studies support the notion that early onset depression and late onset depression have different etiological pathways. Late onset depression has been found to be a heterogeneous group. This study attempts to divide the late onset group in two subgroups with different aetiology and find evidence for the vascular depression hypothesis. METHODS Subjects were 132 depressed elderly persons from the general population, general practitioners and mental health care outpatient clinics. Sixty-four had early-onset depression (< 60), 69 had late-onset depression (> or = 60). The latter group was divided into subjects with (n = 15) and without (n = 15) severe life stress. The groups were compared with respect to a variety of variables including vascular risk factors RESULTS Early-onset depression was associated with neuroticism and parental history. Subjects with late-onset depression and no severe life stress had higher vascular risk factors than whose depression was preceded by a severe stressor did. CONCLUSIONS Our findings suggest that late life depression can be divided into subgroups with different etiological pathways: (1) early-onset with longstanding psychobiological vulnerability; (2) late-onset as reaction to severe life stress; and (3) late-onset with vascular risk factors.

The prevalence of seasonal affective disorder in The Netherlands: a prospective and retrospective study of seasonal mood variation in the general population.

BACKGROUND The aim of the present study was to assess the prevalence of seasonal affective disorder (SAD) in The Netherlands. METHODS The subjects (n = 5356), randomly selected from community registers, were given the Seasonal Pattern Assessment Questionnaire and the Centre for Epidemiological Studies Depression Scale over a period of 13 months. The response rate was 52.6%. RESULTS Three percent of the respondents met the criteria for winter SAD, 0.1% for summer SAD. The criteria for subsyndromal SAD, a milder form of SAD, were met by 8.5%, 0.3% of whom showed a summer pattern. Younger women received a diagnosis of SAD more often than men or older women. CONCLUSIONS SAD subjects were significantly more often unemployed or on sick leave than other subjects. Respondents who met winter SAD criteria were significantly more depressed than healthy subjects, in both winter and summer. Finally, month of completion had no influence on the number of subjects meeting the SAD criteria.

Urinary free cortisol excretion in elderly persons with minor and major depression

Several studies have found that cortisol hypersecretion may occur in severely depressed patients, characterized by melancholic features. On the other hand, illness chronicity seems to be related to low, rather than high, cortisol levels. This study aims to trace factors associated with 24-h urinary free cortisol levels in a sample of 23 elderly persons with major or minor depression and 21 non-depressed control subjects. Depressive episodes were subdivided according to severity and chronicity (i.e. length and recurrence). None of the depressed persons showed unusually high 24-h cortisol levels, and cortisol excretion was not elevated as compared with that in the control group, regardless of subtype of depression. The results suggest, however, that hyposecretion of cortisol may be a feature of chronic depressive episodes, especially in males.

The reliability and validity of the Seasonal Pattern Assessment Questionnaire: a comparison between patient groups

BACKGROUND The Seasonal Pattern Assessment Questionnaire (SPAQ) is a frequently used screening instrument in the research on Seasonal Affective Disorder (SAD). Nevertheless, studies on its reliability and validity are relatively scarce. In the present study the reliability and the contrast validity of the SPAQ are investigated. METHODS SAD patients, selected by means of a clinical interview, non-seasonal depressed out-patients, non-depressed out-patients, and a control group, are contrasted to estimate the discriminating power of the SPAQ. Also, the reliability and factor structure of the seasonality and the climate subscales are investigated. To study food intake the Seasonal Food Preference Questionnaire (SFPQ) was developed. RESULTS The SAD criterion of the SPAQ shows good specificity (94%), but a low sensitivity (44%). Discriminant analysis shows sufficient ability to classify subjects (81% correctly classified). The Global Seasonality Scale has a good internal consistency. It consists of two factors, a psychological factor and a food factor. The SFPQ is sensitive for carbohydrate intake by SAD patients. LIMITATIONS Most SAD patients had received treatment and completed the SPAQ while they were not depressed, which may have influenced the sensitivity. CONCLUSIONS The SPAQ is not sensitive enough to be considered a diagnostic instrument for SAD. Nevertheless, it is accurate enough to be used as a screenings instrument. The only false positives were found in the depressive group. The accuracy of prevalence Figs. can be improved by completion of the SPAQ in the summer months, combined with the completion of a depression scale.

Changes in sleep polygraphic variables and clinical state in depressed patients during treatment with citalopram

Drug-induced improvement of depression may be mediated by changes in sleep physiology. The aim of this study was to relate changes in sleep polygraphic variables to clinical state during treatment with citalopram, a highly specific serotonin uptake inhibitor. Sixteen patients took part. The study was single-blind and uncontrolled. A 1-week wash-out period was followed by 1 week of placebo administration, a medication period of 5 weeks, and a 1-week placebo period. For the entire group a significant decrease of rapid eye movement sleep (REMS) and a significant lengthening of REMS latency were observed initially as well as at the end of treatment. No changes in sleep continuity were found, but non-REMS stage 2 (percentage) was significantly increased. On the basis of clinical change, as expressed by the scores of the Hamilton Rating Scale for Depression, at the end of the citalopram treatment the patient group was split in two halves: eight less and eight more improved patients. The groups did not differ with respect to any sleep polygraphic varible.

Nonverbal interpersonal sensitivity and persistence of depression : Perception of emotions in schematic faces

Deficits in the decoding of facial emotional expressions may play a role in the persistence of depression. In a prospective longitudinal study, 33 depressed outpatients (30 major depression, 2 dysthymia, and 1 cyclothymic disorder) judged schematic faces with respect to the emotions they expressed (fear, happiness, anger, sadness, disgust, surprise, rejection, and invitation) at admission (T0) and again 6 and 30 weeks later. Severity of depression (BDI) was assessed at these three times. Those patients who perceived less sadness, rejection, or anger in faces at T0 were less likely to show a favorable course of depression after 6 weeks (sadness, anger) or after 30 weeks (sadness, rejection, anger). These relationships could not be ascribed to initial levels of depression, age, or gender. The perception of sadness and rejection did not change over time, and therefore may have trait-like qualities. Depression appears to be more persistent in the subgroup that is hyposensitive to (negative) facial signals.

The judgment of facial expressions by depressed patients, their partners and controls

BACKGROUND Research has shown that cognitive and interpersonal processes play significant roles in depression development and maintenance. Depressed patients judgments of emotions displayed in facial expressions, as well as those of their partners, allow for better understanding of these processes. METHODS In this study, twenty major depression outpatients, their partners and control persons (matched on the sex and age of the partner) judged facial expressions as to the emotions they felt were portrayed, at the patients outpatient admission. It was expected that the patients would judge the facial expression more negatively and less positively than their partners and that the partners would judge more negatively and less positively than the controls. RESULTS It was found that while both the patients and partners judged less positive emotions than the controls, the patients and partners did not judge the expressions differently. A trend in the same direction was found between the three groups as to judgment of negative emotions. CONCLUSION These findings are related back to interpersonal and cognitive theories of depression. LIMITATION A limitation of this study was the somewhat small patient population available for study. CLINICAL RELEVANCE This study helps to shed light on the similarity between interpersonal and cognitive processes of depressed patients and their partners.

Potential psychosocial mechanisms linking depression to immune function in elderly subjects

Although depression and immune changes in elderly subjects constitute a considerable health risk, mechanisms underlying the association between depression and immune function are unclear. The question of whether personality and social support can explain the variation in immune function during depression was addressed in 21 elderly depressive and 23 control subjects. The following variables were studied: neuroticism, extraversion, received social support, depression-related immune parameters [i.e. numbers of lymphocytes, lymphocyte subsets CD3+, CD8+, natural killer-like T cells (NKT), CD4/CD8 ratio, and interleukin-6 (Il-6)]. We found that neuroticism reduced the association between depression and Il-6 (from 62 to 22.4%) and between depression and CD3+ (from 27.6 to 21.6%), and was also directly related to Il-6 (i.e. adjusted for age and depression). Social support reduced the association between depression and NKT cells from 25 to 18%, while it was also directly related to NKT cells. Extraversion, adjusted for age and depression, was negatively related to CD4/CD8 ratio. Subjects with high extraversion and high social support had more NKT cells. We concluded that changes in immune function during depression can partly be explained by neuroticism and received social support, whereas immune function is also directly related to these psychosocial variables. Neuroticism may exert its contribution to the risk for depression partly via Il-6 production.

Relationship between perception of facial emotions and anxiety in clinical depression: Does anxiety-related perception predict persistence of depression?

Within the framework of interpersonal theories on depression, it was postulated 1) that an anxiety-related mood-congruent bias with respect to the perception of facial expressions could be demonstrated in clinically depressed patients: 2) that the perception of negative facial emotions would be associated with co-occurring anxiety levels rather than with depression, and 3) that the putative anxiety-related bias would predict the subsequent course of depression. Such relationships would support the possible causal role of negative biases for the persistence of depression. Thirty-nine depressed patients (thirty-six patients met the criteria for major depression, two had a dysthymic disorder and one patient suffered from a cyclothymic disorder) were studied. The patients judged schematic faces with respect to the emotions they express (fear, happiness, anger, sadness, disgust, surprise, rejection and invitation) at admission (T0), and after 6 (T1) and 30 (T2) weeks. Severity of depression (BDI) and anxiety (SCL-90) were assessed at these three points. We found considerable support for the first 2 hypotheses: a) The perception of negative emotions was related to anxiety but not to depression (at T0 this association was significant and at T1 and T2 tendencies were found); b) When the level of depression was controlled for, significant relationships remained (emerged) between anxiety and the perception of negative emotions at each of the three different time points; c) Anxiety and perception of negative emotions covaried within subjects when large changes in depression/anxiety were involved, i.e. after 30 weeks. This relationship disappeared when depression change was partialled out. The third hypothesis was not confirmed: The perception of negative emotions did not predict the course of depression. Although a direct relationship with depression persistence and a negative bias in the perception of interaction-relevant stimuli (i.e. facial emotions) in anxious depressed patients could not be found, the existence of such anxiety-related negative bias forms indirect evidence for the notion that this negative bias may mediate rejective attitudes of others towards depressives and consequently may contribute to an unfavorable course of depression.