Traumatic Events May Affect Psychiatric Disorder Development, Moreso Than Familial Factors
Assault, bereavement, and injury were significantly associated with an increased risk of subsequent psychiatric disorders, independent of familial background, in a nationwide cohort study recently published in JAMA Psychiatry.
“While the role of familial factors in psychiatric disorders have been demonstrated, our findings indicate that familial factors may have limited influence on the occurrence of psychiatric disorders in the context of severe trauma or bereavement,” authors noted. “The risk elevation observed immediately after these events motivates early clinical surveillance and mental health services for these vulnerable populations.”
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Researchers evaluated 3 cohorts of individuals in Sweden who had not been diagnosed with a psychiatric disorder prior to a traumatic event from January 1987 to December 2013. Those individuals’ siblings who had not experienced a traumatic event were also included in the evaluation. Exposed individuals were also each paired with 10 participants who had not been exposed to an assault, injury, or bereavement who were matched by age, sex, and birthplace. Data were gathered from the Swedish Total Population Register and were analyzed from March 2022 to April 2023. Considered traumatic events included physical or sexual assault, TKTK injury, or the death of a child, spouse, or partner and were diagnosed in a hospital setting or in specialized psychiatric clinics. Separate sibling cohorts were established for assault (exposed individuals = 34,894; unexposed siblings = 56,534), injury (exposed individuals = 388,077; unexposed siblings = 629,434), and bereavement (exposed individuals = 191,034; unexposed siblings = 372,665).
At age of assault, injury, and bereavement, participants had a median age of 22, 19, and 60, respectively. A median follow-up of 4.9, 9.1, and 8.1 years showed the incidence rates of any psychiatric disorder were 38.1, 13.9, and 9.0 per 1000 person-years for the exposed groups of the 3 cohorts, respectively. Researchers noted that risk of any psychiatric disorder was elevated during the first year after the traumatic event (assault hazard ratio [HR], 4.55; 95% CI, 4.34-4.77), injury (HR, 3.31; 95% CI,3.23-3.38), bereavement (HR, 2.81; 95% CI, 2.72-2.91) and continuing every year thereafter (assault HR, 2.50; 95% CI, 2.43-2.56; injury HR, 1.69; 95% CI, 1.68-1.70; bereavement HR, 1.42; 95% CI, 1.40-1.44). Comparable associations were obtained in sibling comparison (first year: assault HR, 3.70; 95% CI, 3.37-4.05; injury HR, 2.98; 95% CI, 2.85-3.12; bereavement HR, 2.72; 95% CI, 2.54-2.91; thereafter: assault HR, 1.93; 95% CI, 1.84-2.02; injury HR, 1.51; 95% CI, 1.48-1.53; bereavement HR, 1.35; 95% CI, 1.31-1.38). The greatest HR following a traumatic event was post-traumatic stress disorder (PTSD) following a sexual assault (sibling comparison HR, 4.52; 95% CI, 3.56-5.73 during entire follow-up period).
Authors acknowledged that underestimated psychiatric disorder incidence rates could have limited study results as well as their inclusion of more severe traumatic events and exclusion of less severe events. They also noted that surveillance bias could have been at play as well.
“The associations between assaults and psychiatric disorders remained significant in the sibling comparisons, indicating at most modest influence of familial factors,” authors concluded. “Thus, further studies on the role of familial factors in psychiatric disorders may benefit from incorporating data on major life events or trauma.”
