Post-traumatic stress disorder (PTSD) refers to a set of psychiatric symptoms that develop after exposure to an event that causes sudden and intense distress. The person is unable to process the traumatic memory as a past event: it continues to impose itself in the present, in the form of flashbacks, avoidance, and hyperactivation of the nervous system. This disorder can appear a few weeks after the shock or manifest months later.
Automatic survival responses: beyond fight or flight
When danger arises, the brain triggers a physiological cascade even before conscious thought intervenes. The heart rate accelerates, muscles tense, digestion stops, and the released cortisol dulls pain but clouds rational thinking. This mechanism is known as the fight-or-flight response.
However, recent research describes more varied responses. Three other automatic reactions complete the picture: freeze (stunning, inability to move or speak), flop (collapse, loss of tone, sometimes fainting), and friend (immediate search for social connection for protection). These five responses, often summarized by the expression “the 5 Fs,” are not a choice. They are triggered by the autonomic nervous system.
Understanding these reactions helps affected individuals make sense of their experiences. A victim who did not scream or resist during an assault likely went through an episode of freeze or flop, which reflects neither consent nor voluntary passivity. To understand post-traumatic stress, one must first admit that the response to danger escapes conscious control.
PTSD symptoms: three interrelated domains
The diagnosis of PTSD relies on the prolonged presence of symptoms grouped into three distinct categories. These categories do not function in isolation: they interact and exacerbate each other.
Flashbacks and intrusions
The person relives the traumatic event through intrusive memories, repetitive nightmares, or flashbacks. The physical sensations experienced during the trauma (smells, pains, sounds) can resurface unexpectedly. The memory does not behave like an ordinary memory: it imposes itself with the same emotional intensity as the initial event.
Avoidance and withdrawal
To escape these intrusions, the person develops avoidance behaviors. They flee from places, situations, or people that might remind them of the trauma. This avoidance can lead to partial or total amnesia of the event. Emotional withdrawal sets in: a feeling of constant fog, a sense of being detached from others, difficulty in feeling positive emotions.
Hyperactivation of the nervous system
The third domain concerns a constant state of alertness. Sleep disturbances, irritability, exaggerated startle responses, concentration difficulties: the nervous system remains in “danger” mode long after the event has ended. This hypervigilance exhausts the person physically and mentally, and deeply alters personal, social, and professional life.
Factors contributing to the chronicity of post-traumatic stress
Not all individuals exposed to a traumatic event develop PTSD. The risk depends on pre-existing factors unique to each person, as well as what happens after the shock.
Social support after trauma is a well-documented protective factor. The WHO places it at the center of its recommendations. Conversely, isolation, material difficulties, and the maintenance of a stressful environment after the event significantly increase the risk of chronicity.
The analysis of fire victims in France illustrates this mechanism: when the stress related to losing housing, administrative procedures, and financial uncertainty persists, the traumatic event feels like it never ends. The initial trauma extends into post-event living conditions.
- Social isolation and lack of a support network increase the duration and severity of symptoms
- Persistent material difficulties (loss of housing, precariousness) keep the nervous system in a state of alert
- History of trauma, especially in childhood, sensitizes the stress response system and increases vulnerability
- The quality of immediate care after the event influences medium-term outcomes
Therapeutic management: the triphasic model of trauma
Treating PTSD does not involve immediately diving back into the traumatic memory. Recent approaches favor a three-phase model, which prioritizes stabilization before any work on memories.
Stabilization phase
The first step aims to restore a sense of safety. The therapist works on emotional regulation, reduces episodes of dissociation, and helps the person regain grounding in the present. Without this foundation, reprocessing the trauma risks retraumatizing the patient rather than relieving them.
Reprocessing traumatic memories
Once stabilization is achieved, therapy addresses the memories themselves. Two approaches have a solid evidence base:
- Cognitive-behavioral therapy (CBT), focused on gradual exposure to memories and restructuring thoughts related to the trauma
- EMDR (Eye Movement Desensitization and Reprocessing), which uses bilateral stimulation to facilitate the brain’s reprocessing of memories
- Antidepressants may complement psychotherapy when symptoms are particularly severe
Integration and rehabilitation
The third phase aims for a return to functional living. The person rebuilds their social anchors, resumes activities abandoned during the troubled period, and consolidates therapeutic gains. This phase is often underestimated, even though it conditions the durability of healing.
Complex PTSD: a distinct yet lesser-known form
Complex PTSD (C-PTSD) differs from “classic” PTSD by the nature of the triggering events. While PTSD generally results from a single event, C-PTSD arises from repeated and prolonged traumas: domestic violence, childhood abuse, captivity, persecution.
In addition to the usual PTSD symptoms, there are profound difficulties in emotional regulation, a lasting alteration of self-image, and marked relational disturbances. The prevalence of complex PTSD in the general population varies by study, but it remains significant in populations exposed to chronic violence.
This distinction has direct implications for care. The triphasic model makes sense here: the stabilization phase must be longer and more in-depth before considering direct work on traumatic memories. The influencing factors are multiple: quality of early attachment, experienced discrimination, physical health status, cultural context.
PTSD, whether simple or complex, is not a fatality. Research on the mechanisms of memory resurgence is progressing, and therapeutic protocols are being refined. The most determining factor often remains the simplest to name: the presence of a reliable support network and quick access to appropriate care.