Objectives: To examine whether attachment style moderates the relationship between polygenic risk scores (PRS) for posttraumatic stress disorder (PTSD) re-experiencing (PTSDREX) symptoms and the severity of and positive screen for traumatic loss-related PTSD.
Methods: Data were analysed from 631 US veterans who endorsed 'unexpected death of a loved one' as their 'worst' traumatic event. Multivariable models evaluated the association between PRS for PTSDREX, attachment style, and their interaction in predicting severity and positive screen for PTSD. A gene enrichment analysis was conducted to identify possible molecular mechanisms underlying the association between PTSDREX PRS and PTSD.
Results: PTSDREX PRS (β = 0.17; odds ratio [OR] = 1.85), attachment style (β= -0.33; OR = 0.14), and PTSDREX PRS × attachment style interaction (β= -0.12; OR = 0.53) were significant predictors of the severity and positive screen for PTSD. The most significant gene set detected was the gene ontology (GO) cellular component podosome set (GO:0002102, p < 3.95 × 10-5).
Conclusions: Having a secure attachment style may help mitigate polygenic risk for developing traumatic loss-related PTSD in US veterans. Podosomes, which are implicated in inflammatory and neuroplasticity processes, may contribute to the genetic liability to developing loss-related PTSD. Psychological treatments targeting attachment security may help mitigate increased polygenic risk for loss-related PTSD in this population.
Keywords: Veterans; bereavement; gene–environment interaction; posttraumatic stress disorder (PTSD).