| 1. |
- Chourbaji, Sabine, et al.
(författare)
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CREB-regulated diurnal activity patterns are not indicative for depression-like symptoms in mice and men.
- 2008
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Ingår i: Medical Hypotheses. - : Elsevier BV. - 0306-9877 .- 1532-2777. ; 70:1, s. 117-21
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Tidskriftsartikel (refereegranskat)abstract
- Activation of the transcription factor CREB by Ser142 phosphorylation is implicated in synchronizing circadian rhythmicity, which is disturbed in many depressive patients. Hence, one could assume that emotional behaviour and neuroendocrinological markers would be altered in CREB(S142A) mice, in which serine 142 is replaced by alanine, preventing phosphorylation at this residue. Moreover, associations of CREB Ser142 and seasonal affective disorder (SAD) might be detectable by the analysis of single-nucleotide polymorphisms (SNPs) in the CREB gene close to the Ser142 residue in SAD patients. However, neither CREB(S142A) mice demonstrate features of depression, nor there is evidence for an association of SAD with the CREB genotypes. Nevertheless, in humans there is an association of a global seasonality score and circadian rhythmicity with the CREB genotypes in healthy control probands, but not SAD patients. This parallels the phenotype of CREB(S142A) mice, presenting alterations of circadian rhythm and light-induced entrainment. Thus it is reasonable to assume that CREB Ser142 represents a molecular switch in mice and men, which is responsible for the (dys)regulation of circadian rhythms.
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| 2. |
- Johansson, Carolina, et al.
(författare)
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Seasonal affective disorder and the G-protein beta-3-subunit C825T polymorphism
- 2004
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Ingår i: Biological Psychiatry. - New York : Elsevier. - 0006-3223 .- 1873-2402. ; 55:3, s. 317-319
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Tidskriftsartikel (refereegranskat)abstract
- Background: Guanine nucleotide-binding proteins (G-proteins) have been implicated in affective disorders, with reports of altered signal transduction and G-protein levels. Association with seasonal affective disorder (SAD) has been found for the higher activity T-allele of the G-protein beta-3-subunit C825T polymorphism.Methods. European SAD patients (n = 159) and matched controls (n = 159) were genotyped for the C825T. Seasonality and diurnal preference were investigated in subsets of the material (n = 177 and 92, respectively).Results. We found no association between C825T and SAD (chi(2) = .09, p = .96) or seasonality (F = 1.76, p = .18). There was some evidence for an effect on diurnal preference but only in the control group (n = 46, t = - 2.8, Bonferroni corrected p = .045).Conclusions: These results suggest that the G-protein beta-3-subunit 825 T-allele does not play a major role in susceptibility to seasonal affective disorder in the population studied.
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| 3. |
- Lavebratt, Catharina, et al.
(författare)
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CRY2 is associated with depression
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Background: Abnormalities in the circadian clockwork often characterize patients with major depressive and bipolar disorders. Circadian clock genes are targets of interest in these patients. CRY2 is a circadian gene that participates in regulation of the evening oscillator. This is of interest in mood disorders where a lack of switch from evening to morning oscillators has been postulated.Principal Findings: We observed a marked diurnal variation in human CRY2 mRNA levels from peripheral blood mononuclear cells and a significant up-regulation (P = 0.020) following one-night total sleep deprivation, a known antidepressant. In depressed bipolar patients, levels of CRY2 mRNA were decreased (P = 0.029) and a complete lack of increase was observed following sleep deprivation. To investigate a possible genetic contribution, we undertook SNP genotyping of the CRY2 gene in two independent population-based samples from Sweden (118 cases and 1011 controls) and Finland (86 cases and 1096 controls). The CRY2 gene was significantly associated with winter depression in both samples (haplotype analysis in Swedish and Finnish samples: OR = 1.8, P = 0.0059 and OR = 1.8, P = 0.00044, respectively).Conclusions: We propose that a CRY2 locus is associated with vulnerability for depression, and that mechanisms of action involve dysregulation of CRY2 expression.
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| 4. |
- Partonen, Timo, et al.
(författare)
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Three circadian clock genes Per2, Arnt1, and Npas2 contribute to winter depression
- 2007
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Ingår i: Annals of Medicine. - New York : Informa Healthcare. - 0785-3890 .- 1365-2060. ; 39:3, s. 229-238
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Tidskriftsartikel (refereegranskat)abstract
- Background. Multiple lines of evidence suggest that the circadian clock contributes to the pathogenesis of winter depression or seasonal affective disorder (SAD). We hypothesized that sequence variations in three genes, including Per2, Arntl, and Npas2, which form a functional unit at the core of the circadian clock, predispose to winter depression.Methods. In silico analysis of the biological effects of allelic differences suggested the target single-nucleotide polymorphisms (SNPs) to be analyzed in a sample of 189 patients and 189 matched controls. The most relevant SNP in each gene was identified for the interaction analysis and included in the multivariate assessment of the combined effects of all three SNPs on the disease risk.Results. SAD was associated with variations in each of the three genes in gene-wise logistic regression analysis. In combination analysis of variations of Per2, Arntl, and Npas2, we found additive effects and identified a genetic risk profile for the disorder. Carriers of the risk genotype combination had the odds ratio of 4.43 of developing SAD as compared with the remaining genotypes, and of 10.67 as compared with the most protective genotype combination.Conclusion. Variations in the three circadian clock genes Per2, Arntl, and Npas2 are associated with the disease, supporting the hypothesis that the circadian clock mechanisms contribute to winter depression.
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| 5. |
- Pirkis, Jane, et al.
(författare)
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Suicide numbers during the first 9-15 months of the COVID-19 pandemic compared with pre-existing trends : An interrupted time series analysis in 33 countries
- 2022
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Ingår i: eClinicalMedicine. - : Elsevier. - 2589-5370. ; 51
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Tidskriftsartikel (refereegranskat)abstract
- Background Predicted increases in suicide were not generally observed in the early months of the COVID-19 pandemic. However, the picture may be changing and patterns might vary across demographic groups. We aimed to provide a timely, granular picture of the pandemic's impact on suicides globally. Methods We identified suicide data from official public-sector sources for countries/areas-within-countries, searching websites and academic literature and contacting data custodians and authors as necessary. We sent our first data request on 22nd June 2021 and stopped collecting data on 31st October 2021. We used interrupted time series (ITS) analyses to model the association between the pandemic's emergence and total suicides and suicides by sex-, age-and sex-by-age in each country/area-within-country. We compared the observed and expected numbers of suicides in the pandemic's first nine and first 10-15 months and used meta-regression to explore sources of variation. Findings We sourced data from 33 countries (24 high-income, six upper-middle-income, three lower-middle-income; 25 with whole-country data, 12 with data for area(s)-within-the-country, four with both). There was no evidence of greater-than-expected numbers of suicides in the majority of countries/areas-within-countries in any analysis; more commonly, there was evidence of lower-than-expected numbers. Certain sex, age and sex-by-age groups stood out as potentially concerning, but these were not consistent across countries/areas-within-countries. In the meta-regression, different patterns were not explained by countries' COVID-19 mortality rate, stringency of public health response, economic support level, or presence of a national suicide prevention strategy. Nor were they explained by countries' income level, although the meta-regression only included data from high-income and upper-middle-income countries, and there were suggestions from the ITS analyses that lower-middle-income countries fared less well. Interpretation Although there are some countries/areas-within-countries where overall suicide numbers and numbers for certain sex- and age-based groups are greater-than-expected, these countries/areas-within-countries are in the minority. Any upward movement in suicide numbers in any place or group is concerning, and we need to remain alert to and respond to changes as the pandemic and its mental health and economic consequences continue. Copyright (C) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
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| 6. |
- Raza, Auriba, 1984-, et al.
(författare)
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Daylight during winters and symptoms of depression and sleep problems : A within-individual analysis
- 2024
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Ingår i: Environment International. - 0160-4120 .- 1873-6750. ; 183
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Tidskriftsartikel (refereegranskat)abstract
- Background: With climate change Northern areas of the globe are expected to have less daylight during winters due to less snow and more cloudiness. While wintertime has been linked to mental health problems, the role of wintertime daylight has been scarcely studied. We examined longitudinal associations for wintertime objective exposure to global radiation and self-reported daylight exposure with symptoms of depression and sleep problems.Methods: Our analytical sample included 15,619 respondents from three Swedish Longitudinal Occupational Surveys of Health (2012, 2014 and 2016). Objective exposure was global radiation (MJ/m2, November-January and November-February). Subjective exposure was based on self-reported time spent outdoors in daylight (<1 h vs. ≥ 1 h, November-January). Symptoms of depression were evaluated using a six-item subscale of the (Hopkins) Symptom Checklist. Fixed-effects method with conditional logistic regression controlled for time-invariant participant characteristics by design and time-varying covariates were added into models.Results: One unit increase in the four-month averaged global radiation was associated with lower odds of depressive symptoms (OR 0.69, 95 % CI 0.52–0.91). These findings were confirmed using four-month cumulative exposure (OR 0.91, 95 % CI 0.85–0.98). Individuals reporting ≥ 1 h exposure to daylight during winter months were less likely to report depressive symptoms (OR 0.72, 95 % CI 0.60–0.82) compared to time when their exposure was < 1 h. Higher three-month exposure to global radiation suggested a protective association for sleep problems.Conclusion: These findings suggest that higher exposure to daylight during winters may contribute to lower likelihood of depression symptoms.
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| 7. |
- Sandman, Nils, et al.
(författare)
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Winter is coming : nightmares and sleep problems during seasonal affective disorder
- 2016
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Ingår i: Journal of Sleep Research. - : John Wiley & Sons. - 0962-1105 .- 1365-2869. ; 25:5, s. 612-619
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Tidskriftsartikel (refereegranskat)abstract
- Sleep problems, especially nightmares and insomnia, often accompany depression. This study investigated how nightmares, symptoms of insomnia, chronotype and sleep duration associate with seasonal affective disorder, a special form of depression. Additionally, it was noted how latitude, a proxy for photoperiod, and characteristics of the place of residence affect the prevalence of seasonal affective disorder and sleep problems. To study these questions, data from FINRISK 2012 study were used. FINRISK 2012 consists of a random population sample of Finnish adults aged 25–74 years (n = 4905) collected during winter from Finnish urban and rural areas spanning the latitudes of 60°N to 66°N. The Seasonal Pattern Assessment Questionnaire was used to assess symptoms of seasonal affective disorder. Participants with symptoms of seasonal affective disorder had significantly increased odds of experiencing frequent nightmares and symptoms of insomnia, and they were more often evening chronotypes. Associations between latitude, population size and urbanicity with seasonal affective disorder symptoms and sleep disturbances were generally not significant, although participants living in areas bordering urban centres had less sleep problems than participants from other regions. These data show that the prevalence of seasonal affective disorder was not affected by latitude.
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