First and foremost, it is important to note that the November 13 ESPA survey was directed at all individuals meeting the exposure criteria that could lead to the development of post-traumatic stress disorder (PTSD). Participants included, on the one hand, those directly exposed to the events and relatives of those who died or were injured,^¹ and, on the other hand, first responders.

The recently published article focuses on first responders, defined as anyone who, as part of their professional or volunteer work, was mobilized on the night of November 13, 2015, or in the three weeks that followed. Few studies have examined the prevalence of post-traumatic stress disorder among responders, and little data is available on their use of healthcare services. Furthermore, for the first time in this type of survey in France, we analyzed the reasons why responders with post-traumatic stress disorder and/or depression did not seek treatment.

Between July 7 and November 10, 2016, 663 first responders (firefighters, Paris Civil Security, Red Cross, police, and staff from the Assistance publique-Hôpitaux de Paris (AP-HP)) agreed to participate and completed the questionnaire: 34% were healthcare professionals, 32% were Paris firefighters, 20% were civil protection volunteers, and 14% were law enforcement officers. The prevalence of probable post-traumatic stress disorder was 4.8% and ranged from 3.4% (firefighters) to 9.5% (police) depending on the responder category.

The study of factors associated with PTSD (complete or partial), which was the subject of a previous publication, identified several factors that can help identify at-risk populations and thus guide screening and care: low educational attainment, having responded to an unsafe scene, and feelings of social isolation. Preparation and training, meanwhile, appear to play a protective role against PTSD. This underscores the importance of continuing training and awareness-raising efforts for all personnel involved in the aftermath of terrorist attacks.

This new publication shows that among responders presenting with full or partial post-traumatic stress disorder or depression, nearly two-thirds had not initiated regular psychological follow-up. The initiation of regular psychological care is associated with a history of psychological care, post-immediate psychological support, and the presence of full or partial PTSD or depression. Among individuals with full or partial PTSD or depression, the reasons cited for not seeking care were: failure to recognize the need for care, organizational reasons, financial reasons, and fear of being stigmatized.

Our results indicate that access to regular psychological care for personnel who responded to these attacks must be improved.

Our findings show that a large proportion of first responders who needed care did not receive it. Several complementary approaches can be implemented to encourage the use of care services. First, information and training on mental health issues that may arise following a potentially traumatic incident must be strengthened. Indeed, due to their profession and culture, it is difficult for first responders to admit that they may need care. It is therefore essential to help first responders become aware of these risks, train them to recognize the symptoms of disorders that may arise, and encourage them to share this with their colleagues or healthcare professionals. This aspect must therefore be an integral part of their skills and professional standards. Information and training can be provided during the initial training of first responders but should also be continued throughout their careers. Ad hoc awareness-raising initiatives could also be conducted following a potentially traumatic incident.

Furthermore, our results also reveal a virtuous cycle where immediate support facilitates post-incident follow-up, which in turn fosters awareness of the need to seek care. Implementing immediate and post-incident support therefore appears to be a promising avenue to encourage the use of care services.

Our results also indicate that the practical arrangements for accessing care must be tailored as closely as possible to the needs of responders. For some, it may be easier to seek support within their own institution; for others, however, the therapist should be external to the institution, without this becoming a financial barrier or the process being too complicated to implement.

Finally, mental health assessments for first responders could be systematically offered following potentially traumatic events such as terrorist attacks. This is, for example, what was offered to all Paris firefighters who responded to the attacks of November 13, 2015. Routine annual assessments could also be implemented, allowing for an annual review and the provision of care before disorders become chronic.

A study conducted by the Nice University Hospital, with contributions from Santé publique France, on hospital staff exposed to the July 14, 2016, attacks also showed similar results: a 9% prevalence of PTSD and low utilization of care, as fewer than 30% of staff members diagnosed with PTSD sought regular psychological follow-up.

Longitudinal studies of responders to the September 11, 2001, attacks in New York show a highly variable impact depending on the individual: some exhibit symptoms that persist for several years after exposure, others show improvement in their condition, and still others who showed no symptoms one year later developed symptoms later on. Apart from these American studies, post-attack research consists mainly of cross-sectional studies, which do not allow for an understanding of changes over time or possible causal links. This is why a second phase of the survey was launched five years after the November 13, 2015, attacks, aimed at estimating the longer-term psychotraumatic impact and changes between the first and second phases. This survey will also help describe and compare the use of support services since the attacks. This second phase of ESPA November 13 took place from November 6, 2020, to April 5, 2021. Nearly 500 respondents participated, about two-thirds of whom had already taken part in the first phase. The initial results are expected by the end of 2022.

It is essential to continue long-term research to better understand reactions and responses to the attacks, as well as the factors that influence them. To fully understand the consequences of the attacks on French society and the factors at play, it is necessary to compare them with similar events in other countries. With this in mind, strengthening international collaboration is essential.