Jump to content

Seasonal effects on suicide rates

Add links
From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Prof Haeffel (talk | contribs) at 18:04, 8 April 2012 (→Popular belief). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Research suggests that the prevalence of suicide is actually greatest during late spring and early summer months/seasons,[1] despite the common belief that suicide rates peak during the cold and dark months of the winter season.[2]

United States National Research Studies

The Center for Disease Control and Prevention and the National Center for Health Statistics report that suicide rates in the United States are lowest during the winter months and highest in the summer and springtime. F. Stephen Bridges’s article “Seasonal Changes in Suicide in the United States, 1971 to 2000”, asserts that there is "A high incidence in early spring (April and May) and…also a low incidence in winter" of suicides. The Bridge's study assessed suicide risk by examining the monthly distribution of suicides within the same time period from of the 1970s, 80s, and 90s as well as via a "harmonic time series model" with six observable harmonic cycles within given year. The results indicated a consistent pattern of suicide risk with most suicides occurring in the spring/summer and the fewest during the winter months. Specifically, Bridge's found that in the 1970's "about 47% of the total variances can be explained by the seasonal components" within that given decade (with more suicides in spring/summer). The period from 1980-1990 in the study indicated, "The seasonal component of suicide incidence for the time period 1981 through 1990 is clearly significant and records about a 27.7% increase in seasonal contribution by comparison with the previous period". For the 1990-2000 time period, the study reports that "the significant seasonal rhythm were explained in 63% of the total variation." [3].

French sociologist Émile Durkheim found a similar pattern of results. Durkheim reported that most suicides occurred in the spring, but not summer. Durkheim believed that sociological cognizance rather than the role of nature was responsible for his findings. Durkheim's posited that most suicides took place in spring because "everything begins to awake; activity is resumed, relations spring up, interchanges increase. In other words, it is the density of human interactions, and not the environment that caused higher incidence of suicide in spring or summer." [4]. Other researchers who have found an association between seasonality and suicide have also concluded that suicides tend to peak during the spring or summer. [5], [6].

International Research Studies

According to F. Stephen Bridges[3], recent research from industrialized countries (including Finland, Sweden, Australia and New Zealand, England, and Wales) has provided enough information to show a decrease of suicide seasonality over the past few decades. Within the country of Greece, research studies indicate that the seasonal variations of mortality due to suicide are “more frequent during the spring and summer months…but no regular annual rhythm”. The researchers that conducted these studies also indicated that "the seasonal variation of suicide follows more closely the seasonal variation of sunshine rather than the corresponding variation of temperature". [7] Studies of Brazil in the Southern Hemisphere have indicated that "the peak number of suicides occurred in spring (November) in men and women of Rio Grande do Sul state and in men of Parana and Santa Catarina states, and in early summer (January) for women of Parana´ state." [8] Few scientific assessment studies that have focused on seasonal suicide variations within the southern hemisphere.

Eleni Petridou conducted a collaborative international study related to seasonal effects on suicide rates that involved twenty different countries. The results showed an early summer peak in suicides. Her conclusion indicates that “seasonal variation in suicide incidence could be explained by the increase in sunshine in summer months because of a relationship between sunshine, high temperatures and suicide rate.” [9]. Australian researchers, J. Edwards and F. Whitlock, doing similar work found a “spring peak in the number of suicides committed in Brisbane, Australia, but the results were not statistically significant…and also that Dublin reported that the incidence of suicide varied according to seasons in the northern hemisphere, but contrary results were found for the southern hemisphere.” [10].

In stark contrast to the actual data, many people believe that suicide rates peak during the winter months. Intuitively this makes sense because of seasonal affective disorder and studies of depression during winter months. Harsher weather, increased prevalence of communicable diseases such as pneumonia and hypothermia, and the minimal amount of sunlight are all stressors common to winter time. [11]. Some also believe that “holiday cheer amplifies loneliness and hopelessness in people who have lost loved ones, or who have high expectations of renewed happiness during the holiday season, only to be disappointed.” [12]. However, despite this array of stressors and possible risk factors, the data is relatively consistent showing that suicide rates are greatest in spring/summer and lowest in fall/winter.

References

  1. ^ [Clauss-Ehlers, Caroline. (2010). Encyclopedia of Cross-Cultural School Psychology, Volume 2, 961]
  2. ^ [Romer, Dan. (2001). Media Continue to Perpetuate Myth of Winter Holiday – Suicide Link. The Annenberg Public Policy Center]
  3. ^ a b [Bridges, F. S.; Yip, P. S. F.; Yang, K. C. T. (2005). Seasonal changes in suicide in the United States, 1971 to 2000. Perceptual and Motor Skills, 100, 920-924.]
  4. ^ [Kposowa, Augustine J., D’Auria, Stephanie. (2010) Association of temporal factors and suicides in the United States, 2000–2004. Social Psychiatry Epidemiology, 45, 433-445.]
  5. ^ [Kalediene R, Starkuviene S, Petrauskiene J. (2006). Seasonal patterns of suicides over the period of socio-economic transition in Lithuania. BMC Pub Health, 6, 40.]
  6. ^ [Petridou E, Papadopoulos FC, Frangakis CE, Skalkidou A, Trichopoulos D. (2002). A role of sunshine in the triggering of suicide. Epidemiology 13, 106–109]
  7. ^ [Bazas, T.; Jemos, J.; Stefanis, K.; et al. (1979). Incidence and Seasonal-Variation of Suicide Mortality in Greece. Comprehensive Psychiatry, 20, 15-20]
  8. ^ [Benedito-Silva, Ana Amelia; Pires, Maria Laura Nogueira; Calil, Helena Maria. (2007). Seasonal variation of suicide in Brazil. Chronobiology International, 24, 727-737]
  9. ^ [Petridou E, Papadopoulos FC, Frangakis CE, Skalkidou A, Trichopoulos D. (2002). A role of sunshine in the triggering of suicide. Epidemiology 13, 106–109]
  10. ^ [Edwards, J.E., Whitlock, F.E. (1968). Suicide and attempted suicide in Brisbane. Med J Psychiatry, 1, 932–938.]
  11. ^ [Deisenhammer, E. A. (2003). Weather and suicide: the present state of knowledge on the association of meteorological factors with suicidal behaviour. Acta Psychiatrica Scandinavica, 108, 402-409.]
  12. ^ [1]
Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Seasonal_effects_on_suicide_rates&oldid=486291145"