We compare a recent Danish twin survey on political attitudes and behaviors to a nationally representative survey covering similar topics. We find very similar means and variances for most of our constructed scales of political attitudes and behaviors in the two surveys, although even small differences tend to be statistically significant due to sample size. This suggests that the twin study can be used to make inferences on the heritability of several political traits in the Danish population.
From the aDepartment of Political Science, University of Copenhagen, Copenhagen, Denmark; bDepartment of Political Science, Stanford University, Stanford, CA; cDepartment of Political Science, Aarhus University, Aarhus, Denmark; dPsychiatric Center Copenhagen, Copenhagen University Hospital, Copenhagen, Denmark; eDepartment of Clinical Medicine, Aarhus University, Aarhus, Denmark; and fPsychosis Research Unit, Aarhus University Hospital, Risskov, Denmark.
Daylight savings time transitions affect approximately 1.6 billion people worldwide. Prior studies have documented associations between daylight savings time transitions and adverse health outcomes, but it remains unknown whether they also cause an increase in the incidence rate of depressive episodes. This seems likely because daylight savings time transitions affect circadian rhythms, which are implicated in the etiology of depressive disorder. Therefore, we investigated the effects of daylight savings time transitions on the incidence rate of unipolar depressive episodes.
Using time series intervention analysis of nationwide data from the Danish Psychiatric Central Research Register from 1995 to 2012, we compared the observed trend in the incidence rate of hospital contacts for unipolar depressive episodes after the transitions to and from summer time to the predicted trend in the incidence rate.
The analyses were based on 185,419 hospital contacts for unipolar depression and showed that the transition from summer time to standard time were associated with an 11% increase (95% CI = 7%, 15%) in the incidence rate of unipolar depressive episodes that dissipated over approximately 10 weeks. The transition from standard time to summer time was not associated with a parallel change in the incidence rate of unipolar depressive episodes.
This study shows that the transition from summer time to standard time was associated with an increase in the incidence rate of unipolar depressive episodes. Distress associated with the sudden advancement of sunset, marking the coming of a long period of short days, may explain this finding. See video abstract at, http://links.lww.com/EDE/B179.
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CommentIn: BMJ. 2016 Oct 31;355:i5857 PMID 27803014
From the aDepartment of Political Science, University of Copenhagen, Copenhagen, Denmark; bDepartment of Political Science, Stanford University, Stanford, CA; cDepartment of Clinical Medicine, Aarhus University, Aarhus, Denmark; and dPsychosis Research Unit, Aarhus University Hospital, Risskov, Denmark.
On 22 July 2011, Anders Breivik killed 77 adults and children in Norway. Having recently documented increases in the incidence of trauma- and stressor-related disorders in Denmark after the 9/11 attacks, we hypothesized that the Breivik attacks-due to their geographic proximity-would be followed by even larger increases in Denmark.
Using population-based data from the Danish Psychiatric Central Research Register (1995-2012), we conducted an intervention analysis of the change in the incidence of trauma- and stressor-related disorders after the Breivik attacks.
The incidence rate increased by 16% over the following 1½ years after the Breivik attacks, corresponding to 2736 additional cases. In comparison, 9/11 was followed by a 4% increase. We also present evidence of a subsequent surge in incidence stimulated by media attention.
This study bolsters previous findings on extra-national consequences of terrorism and indicates that geographic proximity and media coverage may exacerbate effects.