Historical Change of Suicide Seasonality in the Canton of Zurich, Switzerland


  • Suicide data after 1969 were extracted from Swiss mortality records with kind permission of the Swiss Federal Statistical Office in Neuchatel.

Address correspondence to Dr. V. Ajdacic-Gross, ISPMZ, Sumatrastr. 30, CH-8006 Zürich; E-mail: k320256@ifspm.unizh.ch.


Current research is yielding an increasingly heteregeneous picture of suicide seasonalities: They seem to depend on methods and, moreover, they seem to have smoothed in recent decades. This work examines the latter issue by comparing suicide seasonalities in the canton of Zurich, Switzerland, in the 16th–18th centuries, 1901–1920 and 1969–94. The results indicate shifts of peaks and lows on suicide seasonalities over the centuries, with a smoothing of seasonalities toward the 21th century. The recent period does not show any suicide seasonality at all. The canton of Zurich seems to be ahead of the general trend found in other regions of Switzerland.