This retrospective cohort study using Swedish longitudinal, total population registries found that the offspring of suicide decedents who were children or adolescents at the time of parental death were at increased risk of hospitalization for multiple psychiatric outcomes. We also found that the difference in risk of hospitalization for suicide attempt between maternal suicide and accident decedents was higher than for those who lost a father.
Although a study suggested that offspring of suicide decedents were more similar than different from offspring of accident decedents,32
our study suggests that their cumulative risks may be different. The increased risk in offspring of suicide decedents may be attributed to genetic or environmental familial factors that affect both risk for parental suicide and offspring psychiatric outcomes, such as family functioning prior to death, parent-child relationship and parental mental illness not accounted for by parental psychiatric hospitalization.2, 33-36
A family member’s death by suicide may also impact the remaining family differently than death by other means, as they may experience more anger, blame and shame.6, 37
Additionally, a recent study suggested that complicated grief may be higher in individuals who were affected by suicide,38
and such grief has been associated with suicidal ideation among bereaved subjects.39
This study provides further impetus to examine why offspring of suicide decedents are at increased risk of hospitalization for psychiatric outcomes.
We also found that the relative risk of maternal suicide on offspring hospitalization for suicide attempts was larger than the relative risk observed for paternal suicide. The association remained even though we directly compared offspring of suicide decedents with offspring of accident decedents. This finding was congruent with a previous Danish study that suggested a stronger association with offspring suicide in those who lost a mother to suicide.10
Interestingly, we did not find this trend with hospitalization for psychiatric disorders, including depressive disorder. The difference in the findings between hospitalization for suicide attempt and psychiatric disorders supports possible influences of unmeasured risk factors independent of psychiatric hospitalization in families previously affected by suicide.13
Oftentimes, a stronger risk associated with maternal loss than paternal loss is attributed to the loss of a primary caregiver, who is usually the mother.16
If environmental factors related to the sudden loss of a mother as compared to a father play a major role, we would expect parent gender to moderate the relation between parent suicide and offspring risk for hospitalization from a broad range of psychiatric disorders.
The findings should be interpreted in light of some limitations, the most prominent being the registers’ inclusion only of psychiatric disorders severe enough to require hospitalization. Although this limitation may affect the absolute rates of offspring psychiatric morbidity, the relative risks for offspring of suicide decedents, as compared to offspring of accident decedents, are less likely to be affected. Additionally, we did not have detailed information on psychiatric hospitalizations of the parents; therefore, we could not control for hospitalization for specific disorders or for parental suicide attempts. We also focused on biological offspring who were not adopted. Future adoption studies that compare biological versus adopted offspring would be helpful to delineate genetic and environmental influences on parental suicide. Generalizability may be limited to the Western world, since the Swedish population is primarily Caucasian with relatively high socioeconomic status and universal access to health care. Although propensity score matching ensured comparable controls for the cases on measured sociodemographic covariates, unmeasured differences such as genetic or environmental familial confounding may still have been present.40
Additionally, we did not include some offspring of accident decedents when propensity score matching was implemented. This may have decreased the study power, but it has been suggested that having more similar controls, despite the reduced sample size, may actually increase study power.41
It is also important to note that null findings of hospitalization for certain psychiatric disorders do not necessarily imply that parental suicide is not associated with hospitalization of these disorders, but that the risk of being hospitalized for these disorders was not statistically different between offspring of suicide and accident decedents.
Despite these limitations, the population-based data allowed us to conduct a study not feasible in the United States and many other countries. Propensity score matching accounted for measured confounders, resulting in the selection of comparable offspring of suicide and accident decedents, especially on important covariates such as prior psychiatric hospitalization of the parent. The direct comparison with offspring whose parent died in an accident also provided a more clear description of cumulative risks associated with parental suicide, beyond the risks generally associated with sudden parental death. The large sample enabled us to compare the offspring psychiatric hospitalization risks associated with maternal versus paternal suicide, previously difficult to study because maternal suicide is less common than paternal suicide.42
Finally, parental psychiatric morbidity and offspring outcomes were not affected by recall or self-report biases since longitudinal clinical inpatient diagnoses were used across the study population.