Suicide and violence in parents : risk factors and consequences

Suicide and deadly violence directed towards other people are two different expressions of aggression. In family life, lethal violent behaviour may have devastating consequences, obviously for the victims but also for the surviving and bereaved children.

In this thesis, focus is on violent behaviour related to parenthood; violence in the form of suicide as well as violent behaviour directed towards others. The aim has been to identify risk factors of violent expression, for possible use in prevention.

Study I is a matched cohort study of all cases of filicide, the killing of one´s child, in Sweden 1973–2008. Perpetrators of filicide were matched to population controls and further compared to other homicide perpetrators. In 42% of the cases, the perpetrator committed suicide in connection with the offence. Risk factors of filicide were major mental disorder, previous suicide attempt and previous violent offending. No independent effect of substance use disorder was found.

Study II is a nested case-control study of men who killed women with whom they had children. The study includes all cases in Sweden 1973–2009. Children who were bereaved of their mother were followed over time and the risk of adverse events were measured. The association of perpetrator status and major mental disorder was found to be substantial. Similar to Study I, no effect of substance use disorder was found. The children who were bereaved below the age of 18, more often developed mental disorder and substance use disorder and engaged in violent crime and self-harm, compared to controls.

Study III is a nested case-control study, including all mothers aged below 40 who committed suicide in Sweden 1974–2009. When calculating risk of suicide during the first year after giving birth compared to later, a minor decrease in the suicide rate was found. Suicides that occurred during the first year after delivery showed an association to current mental disorder and also to a history of self-harm.

Mental disorder was associated with violence against others (Study I & II) and with suicide (Study III). Previous self-harm was considered a risk factor for both suicidal and violent behaviour and, on the other hand, exposure to violence seems to affect the risk of later mental disorder and suicidal behaviour.

The associations found in these studies cannot be interpreted in terms of causality. This limitation primarily derives from the use of register data. However, the large samples in the presented studies have yielded reliable estimates that could lead to improved detection of individuals at risk.

List of scientific papers

I. Lysell H, Runeson B, Lichtenstein P, Långström N. Risk Factors for Filicide and Homicide : 36-Year National Matched Cohort Study. Journal of Clinical Psychiatry 2014;75: 127-132
https://doi.org/10.4088/JCP.13m08372

II. Lysell H, Dahlin M, Långström N, Lichtenstein P, Runeson B. Killing the Mother of One’s Child : Psychiatric Risk Factors Among Male Perpetrators and Offspring Health Consequences. Journal of Clinical Psychiatry 2016.
https://doi.org/10.4088/JCP.14m09564

III. Lysell H, Dahlin M, Viktorin A, Ljungberg E, Almqvist C, D’Onofrio BM, Dickman P, Runeson B. Maternal Suicide – Register Based Study of All Suicides Occurring After Delivery in Sweden 1974–2009. [Manuscript]