How and when the parent died strongly influenced their child's risk, the researchers report. And because the findings show that parental suicide affects children and teens more profoundly than young adults, it is likely that environmental and developmental factors, as well as genetic ones, are at work in next-generation risk, the scientists say.
"Losing a parent to suicide at an early age emerges as a catalyst for suicide and psychiatric disorders," says lead investigator Holly C. Wilcox, Ph.D., a psychiatric epidemiologist at Hopkins Children's. "However, it's likely that developmental, environmental and genetic factors all come together, most likely simultaneously, to increase risk."
The good news, the researchers say, is that though children in this group are at increased risk, most do not die by suicide, and non-genetic risk factors can be modified. And there may be a critical window for intervention in the aftermath of a parent's suicide during which pediatricians could carefully monitor and refer children for psychiatric evaluation and, if needed, care.
Family support is also critical, the investigators say.
"Children are surprisingly resilient," Wilcox says. "A loving, supporting environment and careful attention to any emerging psychiatric symptoms can offset even such major stressor as a parent's suicide."
In the United States, each year, between 7,000 and 12,000 children lose a parent to suicide, the researchers estimate.
The current study looked at the entire Swedish population over 30 years, making it the largest one to date to analyze the effects of untimely and/or sudden parental death on childhood development.
U.S. and Swedish investigators compared suicides, psychiatric hospitalizations and violent crime convictions over 30 years in more than 500,000 Swedish children, teens and young adults (under the age of 25) who lost a parent to suicide, illness or an accident, on one hand, and in nearly four million children, teens and young adults with living parents, on the other.
Those who lost a parent to suicide as children or teens were three times more likely to commit suicide than children and teenagers with living parents. However there was no difference in suicide risk when the researchers compared those 18 years and older. Young adults who lost a parent to suicide did not have a higher risk when compared to those with living parents. Children under the age of 13 whose parent died suddenly in an accident were twice as likely to die by suicide as those whose parents were alive but the difference disappeared in the older groups. Children under 13 who lost a parent to illness did not have an increased risk for suicide when compared to same-age children with living parents.
In addition, those who lost parents to suicide were nearly twice as likely to be hospitalized for depression as those with living parents. And those who lost parents to accidents or illness had 30 and 40 percent higher risk, respectively, for hospitalization.
Losing a parent, regardless of cause, increased a child's risk of committing a violent crime, the researchers found.
The researchers did not count suspected suicides, nor did they include children with psychiatric or developmental disorders who were treated before the parent's death or as outpatients, meaning the effects of parental suicide may be even more profound than the study suggests.
Co-investigators on the study included S. Janet Kuramoto, M.H.S., of Hopkins; Paul Lichtenstein, Ph.D., Niklas Långström, M.D. Ph.D., and Bo Runeson, M.D. Ph.D, of the Karolinska Institutet in Sweden; and David Brent, M.D., of the University of Pittsburgh.
The research was funded by the National Alliance for Research on Schizophrenia and Depression (NARSAD), by the National Institute on Drug Abuse and by the Swedish Research Council.