Seasonality and Climatic Associations with Violent and Nonviolent Suicide: A Population-Based Study

Abstract

Background: Using 7-year population-based data on Taiwan, we examined seasonal variation in violent versus nonviolent suicide, and its association with meteorological factors: ambient temperature, relative humidity, atmospheric pressure, rainfall and daily sunshine hours. Methods: We used Taiwan’s nationwide mortality data from 1997 to 2003, categorizing the sample decedents into two groups, violent (ICD-9-CM codes E953–E958) and nonviolent (E950–E952) suicide, based on the suicide method used. Seasonal autoregressive integrated moving average (SARIMA) modeling was used to detect seasonality of suicide, and the association of climate variables with violent versus nonviolent suicide. Results: The SARIMA test of seasonality was significant for both genders and the pooled sample (all p < 0.001) in violent suicide deaths, but not nonviolent suicides. Seasonal trends show a significant peak in March–May (early to late spring) for violent suicides. Increasing ambient temperature predicted increasing violent suicide rates. Conclusions: We conclude that seasonality exists in violent but not nonviolent suicide rates. Our findings suggest that suicide is a heterogeneous phenomenon and violent suicide may be more influenced by biochemical and chronobiological mechanisms.

Gender differences in antidepressant use-related seasonality change in suicide mortality in Hungary, 1998–2006

“…In agreement with the prior study of us ) and Oravecz et al (2006) these fi ndings also indicate that decreasing seasonality of suicides could be a good marker of lowering rate of depression-related suicides in the population, particularly in males who use much more frequently violent suicide methods (Maes et al 1993;Kim et al 2004;Lin et al 2008). As gender distribution, method preference, psychiatric morbidity and seasonality of suicides in Hungary (Murphy 2000;Voracek et al 2004;Berecz et al 2005;Kalmar et al 2008) is the same as in other European and North American countries (Murphy 2000;Maes et al 1993;Voracek et al 2004;Oravecz et al accompanied by a sharp increase of suicide mortality in that age-groups while suicide rates further de creased in older people where the utilization of ADs further increased or declined only slightly.…”

“…Whether our fi ndings on the gender differences in antidepressant userelated seasonality change of suicide mortality are independent of the type of suicide methods (violent vs. non-violent) or restricted only to violent suicides, which have been shown to have more marked seasonality (Maes et al 1993;Lin et al 2008) remains an open question and is the subject of further studies.…”

“…However, in spite of the same amount of change in AD consumption and suicide rate in both genders, we found a signifi cant decline in seasonality of suicides, as refl ected in the decreased seasonal index, only in males (Table II). One explanation of this could be the higher base rate of suicide mortality in males, as discussed above, particularly if we consider the fact that seasonality of suicide is more pronounced among males and among those who use violent suicide methods, methods that are characteristic primarily for males (Meares et al 1981;Maes et al 1993;Rihmer et al 1998;Preti 2002;Kim et al 2004;Lin et al 2008;Postolache et al in press;Reutfors et al in press). Another explanation could be that males are more likely than females to benefi t from increased use of appropriate mental health services, because they are less likely to use them (Rihmer and Rutz 2009).…”

The influence of a major disaster on suicide risk in the population

“…It has been demonstrated that methodological choices can substantially influence the findings of changes after a disaster event (Norris, 2006), and an important limitation of extant studies of the September 11, 2001 disaster is that they have generally failed to account for variation in long-and short-term trends in suicide rates in their analytic approach (Dominici, Levy, & Louis, 2005;Lin, 2008). Traditional pre-and postdisaster comparisons may not control for time-varying factors that may be coincident with the study timeframe or explicitly test the causal nature of the exposureoutcome relationship (Kerlinger & Lee, 2000).…”

Climate variations: Risk factor of commiting suicide

“…Sarina test je statistički značajan za oba pola (p<0,001) za nasilne, ali ne i za nenasilne suicide. Isto tako, dokazan je porast suicida s porastom sobne temperature [12].…”