Less recent sun, more suicide (similar title to our short video: less sun, more disease) – Sept 2014

Direct Effect of Sunshine on Suicide

JAMA Psychiatry. Published online September 10, 2014. doi:10.1001/jamapsychiatry.2014.1198 Benjamin Vyssoki, MD1; Nestor D. Kapusta, MD, PhD2; Nicole Praschak-Rieder, MD, PhD1; Georg Dorffner, PhD3; Matthaeus Willeit, MD, PhD1
Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
2Department of Psychoanalysis and Psychotherapy, Medical University of Vienna, Vienna, Austria
3Section for Artificial Intelligence, Medical University of Vienna, Vienna, Austria

Importance It has been observed that suicidal behavior is influenced by sunshine and follows a seasonal pattern. However, seasons bring about changes in several other meteorological factors and a seasonal rhythm in social behavior may also contribute to fluctuations in suicide rates.

Objective To investigate the effects of sunshine on suicide incidence that are independent of seasonal variation.

Design, Setting, and Participants Retrospective analysis of data on all officially confirmed suicides in Austria between January 1, 1970, and May 6, 2010 (n = 69 462). Data on the average duration of sunshine per day (in hours) were calculated from 86 representative meteorological stations. Daily number of suicides and daily duration of sunshine were differentiated to remove variation in sunshine and variation in suicide incidence introduced by season. Thereafter, several models based on Pearson correlation coefficients were calculated.

Main Outcomes and Measures Correlation of daily number of suicides and daily duration of sunshine after mathematically removing the effects of season.

Results Sunshine hours and number of suicides on every day from January 1, 1970, to May 6, 2010, were highly correlated (r = 0.4870; P < 10−9). After differencing for the effects of season, a mathematical procedure that removes most of the variance from the data, a positive correlation between number of suicides and hours of daily sunshine remained for the day of suicide and up to 10 days prior to suicide (rmaximum = 0.0370; P < 10−5). There was a negative correlation between the number of suicides and daily hours of sunshine for the 14 to 60 days prior to the suicide event (rminimum = −0.0383; P < 10−5). These effects were found in the entire sample and in violent suicides.

Conclusions and Relevance Duration of daily sunshine was significantly correlated with suicide frequency independent of season, but effect sizes were low. Our data support the hypothesis that sunshine on the day of suicide and up to 10 days prior to suicide may facilitate suicide. More daily sunshine 14 to 60 days previously is associated with low rates of suicide. Our study also suggests that sunshine during this period may protect against suicide.

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See also VitaminDWiki

• Suicide associated with low vitamin D - many studies
• Does Less Sun Mean More Disease 5 minute video
• All items in category Depression and Vitamin D 219 items

See also web

• Sunshine has a complex relationship with suicide, according to newly published research Vitamin D Council Sept 2014
  There was a positive correlation between number of suicides and hours of daily sunshine for the day of the suicide and up to 10 days prior to suicide. (p<0.001)
  There was a negative correlation between number of suicides and hours of daily sunshine for the 14 to 60 days prior to the suicide.
  Reaserchers stated “In line with our hypothesis, we were able to show that sunshine has an effect on suicides independent of seasonal rhythms. Two main results emerged from our data. First, sunshine on the day of suicide and up to 10 days prior to suicide seems to facilitate suicide, as we found a positive correlation between the duration of sunshine and suicide numbers in this period. Second, to our knowledge, this is the first study to show that sunshine, after removal of seasonal variance in suicide numbers and sunshine duration, may also have a protective effect against suicide.”(p<0.001)