Gender Differences in Risk Factors for Suicide: Findings from a Swedish National Cohort Study
von Borczyskowski, Annika, Lindblad, Frank, Vinnerljung, Bo, Hjern, Anders, Canadian Journal of Psychiatry
Objective: To investigate whether childhood sociodemographic factors and parental psychopathology affect suicide risk differently in men and women.
Method: Cox regressions were used to calculate interaction effects of gender for childhood and parental risk factors for 8815 suicides (27% women) in a national cohort of 2.47 million people born between 1946 and 1968.
Results: Low parental socioeconomic status increased suicide risk only for men, hazard ratio (HR) = 1.22 (P = 0.003 for gender interaction), while living in a metropolitan area increased the risk only for women, HR = 1.42 (P < 0.001 for gender interaction). Parental psychotic or affective disorder increased suicide risk more strongly for women (HR = 2.08), than for men (HR = 1.52) (P = 0.004 for gender interaction).
Conclusion: Growing up in an urban environment and parental psychotic or affective disorder are significant gender-related risk factors for suicide, both conveying higher risks in women. The mechanisms linking childhood urbanicity to increased risk of suicide in adult women stand out as an important research area for the future.
Can J Psychiatry. 2009;55(2): 108-111.
* Parental psychotic or affective disorder increases risk in offspring to commit suicide more strongly in women than in men.
* Growing up in a metropolis increases suicide risk in women.
* Knowledge about these increased risks should guide prevention programs.
* Men tend to use more violent methods to commit suicide, which might make identifying suicides by males easier than in females.
* Data on parental psychopathology was based only on inpatient admission.
* Data on parental psychopathology refers to the years when the study subjects were adults.
Key Words: suicide, risk factor, gender, urbanicity
Abbreviations used in this article
HR hazard ratio
ICD International Classification of Diseases
NCDR National Cause of Death Register
RTP Register of the Total Population
SES socioeconomic status
Suicide death is considerably more common in men than in women in most countries,1^ with a few exceptions such as China, where suicide rates for men and women are equal or even higher for women.5'6 Risk factors for suicide - concerning SES, urbanicity, family structure, and mental illness - have also been investigated from a gender perspective. Being unemployed may increase the suicide risk more for men than for women.3 However, women tend to be more vulnerable to the accumulation of risk factors in an urban environment.7 Being single seems to increase the suicide risk more for men3 and being a parent,8 especially of a young child (aged 2 years or younger),3 is protective against suicide in women. Findings on adult psychiatric illness are not conclusive; one study reported a higher risk for women,3 while no differences between sexes were reported in another.9 A history of prior psychiatric illness has been associated with a narrowing of the male-female difference in suicide rates.5
To our knowledge, no previous study has addressed gender aspects of similar childhood demographics - SES, urbanicity, family structure, and parental mental illness - for risk of suicide. Small numbers, especially about women who die by suicide, and difficulties to obtain reliable information retrospectively are obstacles. In our study, we used the Swedish national registers to approach these methodological challenges, aiming at investigating whether childhood sociodemographic factors, as well as parental psychopathology of various kinds, affect suicide risk differently in men and women.
The study population consisted of people (n = 2 47 1 496) born between 1946 and 1968, who were residents in Sweden on December 31,1 986, according to the RTP and had at least one biological parent (identified to be a Swedish resident in the census of 1 960) recorded in the multigeneration register. …