Posttraumatic stress disorder and depression after the 2018 Strasbourg Christmas Market terrorist attack: a comparison of exposed and non-exposed police personnel

Background: Police personnel are among the first responders exposed to terrorist attacks, raising in number in the late decades. Due to their profession, they are also exposed to repetitive violence, increasing their vulnerability to PTSD and depression. Objective: Our study aims at comparing the prevalence of PTSD and depression, and the risk factors associated with these conditions among directly and indirectly exposed versus non-exposed police personnel during the Strasbourg Christmas Market terrorist attack. Method: Three months after the attack, participants completed a survey assessing their sociodemographic characteristics, occupational data, degree of exposure, sleep debt around the event, event centrality (CES), and three mental health conditions: PTSD (PCL-5), depression (PHQ-9), and suicide risk (yes/no questions). Results: A total of 475 police personnel responded to the questionnaire: 263 were exposed to the attack (182 of them directly) and 212 were non-exposed. Among directly exposed participants, the prevalences of partial and complete PTSD were 12.6 and 6.6%, and the prevalence of moderate-to-severe depression was 11.5%. Multivariate analysis revealed that direct exposure was associated with a higher risk of PTSD (OR = 2.98 [1.10–8.12], p = .03). Direct exposure was not associated with a higher risk of depression (OR = 0.40 [0.10–1.10], p = .08). A significant sleep debt after the event was not associated with a higher risk of later PTSD (OR = 2.18 [0.81–5.91], p = .13) but was associated with depression (OR = 7.92 [2.40–26.5], p < .001). A higher event centrality was associated with both PTSD and depression (p < .001). Conclusions: Police personnel directly exposed to the Strasbourg Christmas Market terrorist attack were at higher risk of PTSD but not depression. Efforts to prevent and treat PTSD should focus on directly exposed police personnel. However, general mental health should be monitored for every personnel member.