Why do suicide rates increase in the spring and decrease in the fall? Insights from Canadian suicide rate and death rate data spanning 2010 to 2020
Abstract
In 1952, the psychiatrist Erwin Stengel hypothesized that suicide becomes rarer in times when the value of life within a society is lower, when death is more common. In Canada, suicide rates and death rates present with consistent seasonality between years, fluctuating inversely with one another. However, the typical pre-pandemic seasonality seen in death rates was broken during the first year of the COVID-19 pandemic, as a consequence of inordinate deaths occurring at an odd time of year. This offers a unique opportunity to observe whether suicide rates were inversely disrupted. The present study models weekly Canadian suicide rates using death rates, from time series data spanning 2010 to 2019. Results indicate that suicide rates decrease on average by 0.27 standard deviations per 1 standard deviation increase in the death rate. This model is then used to predict 2020 suicide rates, using 2020 death rates. Predictions account for 11.6% of the variation in actual 2020 suicide rates. Furthermore, actual 2020 suicide rates display a negative disruption at the same time as the 2020 death rate positive disruption, and this suicide rate disruption is mimicked by our model predictions. Overall, results are interpreted as being favorable towards Stengel’s theory. As alternative interpretation, we suggest that non-suicide-related deaths preferentially remove potential suicides from the population. Overall analysis suggests that elevated death rates during colder seasons are driven by increases in cardiovascular disease (e.g., heart attacks) and communicable disease transmission relative to warmer seasons, resulting in suppressed suicide rates.
Versions
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BibTeX
@misc{wiley2026suicide,
title = {{Why do suicide rates increase in the spring and decrease in the fall? Insights from Canadian suicide rate and death rate data spanning 2010 to 2020}},
author = {James C. Wiley},
howpublished = {PsyArXiv},
year = {2026},
month = sep,
doi = {10.31234/osf.io/aj7bz_v8},
url = {https://osf.io/preprints/psyarxiv/aj7bz_v8/},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Why do suicide rates increase in the spring and decrease in the fall? Insights from Canadian suicide rate and death rate data spanning 2010 to 2020
AU - James C. Wiley
PY - 2026
DA - 2026/09/21
PB - PsyArXiv
DO - 10.31234/osf.io/aj7bz_v8
UR - https://osf.io/preprints/psyarxiv/aj7bz_v8/
AB - In 1952, the psychiatrist Erwin Stengel hypothesized that suicide becomes rarer in times when the value of life within a society is lower, when death is more common. In Canada, suicide rates and death rates present with consistent seasonality between years, fluctuating inversely with one another. However, the typical pre-pandemic seasonality seen in death rates was broken during the first year of the COVID-19 pandemic, as a consequence of inordinate deaths occurring at an odd time of year. This offers a unique opportunity to observe whether suicide rates were inversely disrupted. The present study models weekly Canadian suicide rates using death rates, from time series data spanning 2010 to 2019. Results indicate that suicide rates decrease on average by 0.27 standard deviations per 1 standard deviation increase in the death rate. This model is then used to predict 2020 suicide rates, using 2020 death rates. Predictions account for 11.6% of the variation in actual 2020 suicide rates. Furthermore, actual 2020 suicide rates display a negative disruption at the same time as the 2020 death rate positive disruption, and this suicide rate disruption is mimicked by our model predictions. Overall, results are interpreted as being favorable towards Stengel’s theory. As alternative interpretation, we suggest that non-suicide-related deaths preferentially remove potential suicides from the population. Overall analysis suggests that elevated death rates during colder seasons are driven by increases in cardiovascular disease (e.g., heart attacks) and communicable disease transmission relative to warmer seasons, resulting in suppressed suicide rates.
ER -