European Archives of Psychiatry and Clinical Neuroscience

, Volume 256, Issue 2, pp 98–105

Season–of–birth as a risk factor for the seasonality of suicidal behaviour


    • Centre for Clinical Research in NeuropsychiatryGraylands Hospital
    • School of Psychiatry and Clinical NeurosciencesUniversity of Western Australia
  • D. Greenberg
    • School of Psychiatry and Clinical NeurosciencesUniversity of Western Australia
  • J. Hallmayer
    • Department of Psychiatry and Behavioral ScienceStanford University School of Medicine

DOI: 10.1007/s00406-005-0614-6

Cite this article as:
Rock, D., Greenberg, D. & Hallmayer, J. Eur Arch Psychiatry Clin Neurosci (2006) 256: 98. doi:10.1007/s00406-005-0614-6


Despite implicating the same biological systems, the relationship between suicide seasonality and season–of–birth has not been examined previously. The purpose of this study was to investigate the interaction between season–of–birth and the seasonality of suicidal behaviour. All adult suicides (N = 2923) and deliberate self harm (DSH) hospitalizations (N = 33321) in Western Australia (1970–96) were examined. A variable population at risk approach was used to determine season–of–birth. Seasonality was established by spectral analysis. We found that DSH has a significant season–of–birth (p = 0.047) and seasonality of occurrence, both peaking in spring. Individuals born in the 90 days centred on the peak birth period, however, show no DSH seasonality. In contrast, suicide has no season–of–birth (p = 0.53). We also found a season–of–birth effect among the DSH group that eliminates any seasonality of DSH among the high–risk by birth group. Further work is needed to identify the possible biological and environmental determinants of this interaction.

Key words

seasons suicide/statistics & numerical data birth rate suicide DSH

Copyright information

© Steinkopff-Verlag 2005