Light upon seasonality:seasonality of symptoms in the general population and in patients with depressive and anxiety disorders

The main question of this thesis is the extent to which the seasons influence positive and negative affect in humans. To answer this question, we analysed data in samples of the general population, in patient-oriented settings in primary care and specialised mental healthcare. This thesis shows that on a group level seasonal variation in depressive symptoms, positive and negative affect, is absent or limited in effect size. These findings hold for healthy individuals and for patients who suffer from a depressive disorder (with or without a comorbid anxiety disorder) but unexpectedly also for patients suffering from a seasonal affective disorder as measured with a questionnaire. Further, we found that as the degree of psychopathology increases, significantly more patients attribute their complaints to the change of the seasons. Also, patients suffering from seasonal affective disorder scored high on psychopathology and on a neuroticism scale. We showed that on a population level, seasonal variations in positive and negative affect and depressive symptoms are mainly attributable to high-neurotic subjects. From the literature and our studies, we infer that the psychological mechanism of cognitive attribution is an underestimated factor in seasonal affective disorder. The most important limitation of this thesis is the cross-sectional design of most studies, and as a consequence, the absence of longitudinal measurements within the same individual for all four seasons. We recommend initiating a study with a longitudinal repeated measures approach in order to assess the validity (and temporal stability) of the specifier “with seasonal pattern” for recurrent major depressive disorder and bipolar disorder

Seasonality of mood and affect in a large general population sample

Mood and behaviour are thought to be under considerable influence of the seasons, but evidence is not unequivocal. The purpose of this study was to investigate whether mood and affect are related to the seasons, and what is the role of neuroticism in this association. In a national internet-based crowdsourcing project in the Dutch general population, individuals were invited to assess themselves on several domains of mental health. ANCOVA was used to test for differences between the seasons in mean scores on the Positive and Negative Affect Schedule (PANAS) and Quick Inventory of Depressive Symptomatology (QIDS). Within-subject seasonal differences were tested as well, in a subgroup that completed the PANAS twice. The role of neuroticism as a potential moderator of seasonality was examined. Participants (n = 5,282) scored significantly higher on positive affect (PANAS) and lower on depressive symptoms (QIDS) in spring compared to summer, autumn and winter. They also scored significantly lower on negative affect in spring compared to autumn. Effect sizes were small or very small. Neuroticism moderated the effect of the seasons, with only participants higher on neuroticism showing seasonality. There was no within-subject seasonal effect for participants who completed the questionnaires twice (n = 503), nor was neuroticism a significant moderator of this within-subjects effect. The findings of this study in a general population sample participating in an online crowdsourcing study do not support the widespread belief that seasons influence mood to a great extent. For, as far as the seasons did influence mood, this only applied to highly neurotic participants and not to low-neurotic participants. The underlying mechanism of cognitive attribution may explain the perceived relation between seasonality and neuroticism

The effects of low-intensity narrow-band blue-light treatment compared to bright white-light treatment in sub-syndromal seasonal affective disorder

Background The discovery of a novel photoreceptor in the retinal ganglion cells with a highest sensitivity of 470-490 nm blue light has led to research on the effects of short-wavelength light in humans. Several studies have explored the efficacy of monochromatic blue or blue-enriched light in the treatment of SAD. In this study, a comparison has been made between the effects of broad-wavelength light without ultraviolet (UV) wavelengths compared to narrow-band blue light in the treatment of sub-syndromal seasonal affective disorder (Sub-SAD). Method In a 15-day design, 48 participants suffering from Sub-SAD completed 20-minute sessions of light treatment on five consecutive days. 22 participants were given bright white-light treatment (BLT, broad-wavelength light without UV 10 000 lux, irradiance 31.7 Watt/m2) and 26 participants received narrow-band blue light (BLUE, 100 lux, irradiance 1.0 Watt/m2). All participants completed daily and weekly questionnaires concerning mood, activation, sleep quality, sleepiness and energy. Also, mood and energy levels were assessed by means of the SIGH-SAD, the primary outcome measure. Results On day 15, SIGH-SAD ratings were significantly lower than on day 1 (BLT 54.8 %, effect size 1.7 and BLUE 50.7 %, effect size 1.9). No statistically significant differences were found on the main outcome measures. Conclusion Light treatment is an effective treatment for Sub-SAD. The use of narrow-band blue-light treatment is equally effective as bright white-light treatment

Role of the police in linking individuals experiencing mental health crises with mental health services

BACKGROUND: The police are considered frontline professionals in managing individuals experiencing mental health crises. This study examines the extent to which these individuals are disconnected from mental health services, and whether the police response has an influence on re-establishing contact. METHODS: Police records were searched for calls regarding individuals with acute mental health needs and police handling of these calls. Mental healthcare contact data were retrieved from a Psychiatric Case Register. RESULTS: The police were called upon for mental health crisis situations 492 times within the study year, involving 336 individuals (i.e. 1.7 per 1000 inhabitants per year). Half of these individuals (N=162) were disengaged from mental health services, lacking regular care contact in the year prior to the crisis (apart from contact for crisis intervention). In the month following the crisis, 21% of those who were previously disengaged from services had regular care contact, and this was more frequent (49%) if the police had contacted the mental health services during the crisis. The influence of police referral to the services was still present the following year. However, for the majority (58%) of disengaged individuals police did not contact the mental health services at the time of crisis. CONCLUSIONS: The police deal with a substantial number of individuals experiencing a mental health crisis, half of whom are out of contact with mental health services, and police play an important role in linking these individuals to services. Training police officers to recognise and handle mental health crises, and implementing practical models of cooperation between the police and mental health services in dealing with such crises may further improve police referral of individuals disengaged from mental health services

Seasonality in depressive and anxiety symptoms among primary care patients and in patients with depressive and anxiety disorders; results from the Netherlands Study of Depression and Anxiety

<p>Abstract</p> <p>Background</p> <p>Little is known about seasonality of specific depressive symptoms and anxiety symptoms in different patient populations. This study aims to assess seasonal variation of depressive and anxiety symptoms in a primary care population and across participants who were classified in diagnostic groups 1) healthy controls 2) patients with a major depressive disorder, 3) patients with any anxiety disorder and 4) patients with a major depression and any anxiety disorder.</p> <p>Methods</p> <p>Data were used from the Netherlands Study of Depression and Anxiety (NESDA). First, in 5549 patients from the NESDA primary care recruitment population the Kessler-10 screening questionnaire was used and data were analyzed across season in a multilevel linear model. Second, in 1090 subjects classified into four groups according to psychiatric status according to the Composite International Diagnostic Interview, overall depressive symptoms and atypical versus melancholic features were assessed with the Inventory of Depressive Symptoms. Anxiety and fear were assessed with the Beck Anxiety Inventory and the Fear questionnaire. Symptom levels across season were analyzed in a linear regression model.</p> <p>Results</p> <p>In the primary care population the severity of depressive and anxiety symptoms did not show a seasonal pattern. In the diagnostic groups healthy controls and patients with any anxiety disorder, but not patients with a major depressive disorder, showed a small rise in depressive symptoms in winter. Atypical and melancholic symptoms were both elevated in winter. No seasonal pattern for anxiety symptoms was found. There was a small gender related seasonal effect for fear symptoms.</p> <p>Conclusions</p> <p>Seasonal differences in severity or type of depressive and anxiety symptoms, as measured with a general screening instrument and symptom questionnaires, were absent or small in effect size in a primary care population and in patient populations with a major depressive disorder and anxiety disorders.</p