Post-traumatic stress disorder (PTSD) does not only occur after a spectacular event. Prolonged exposure to domestic violence, a stay in intensive care, or the sudden loss of a loved one can be sufficient.
The majority of people exposed to a potentially traumatic event do not develop this disorder. Understanding what causes some individuals to shift from acute stress to a lasting disorder requires looking beyond the event itself.
Epigenetics and fear circuits: what neurobiology changes in the understanding of PTSD
Research published since 2021 shifts the focus. Vulnerability to PTSD is not solely a result of inherited genetic predisposition. Recent studies describe epigenetic modifications of gene expression due to stress, particularly in individuals exposed to early adverse experiences (abuse, neglect, emotional insecurity).
These modifications durably alter the functioning of three central brain structures: the amygdala, the hippocampus, and the prefrontal cortex. The amygdala, which detects danger, remains in a state of hyperactivation. The hippocampus, responsible for contextualizing memories, loses efficiency. The prefrontal cortex, which is supposed to regulate emotional responses, struggles to inhibit fear signals.
In other words, trauma alters the very mechanisms of memory. The memory is no longer stored as a past event: it resurfaces with the same sensory and emotional intensity as during the initial event, in the form of flashbacks or nightmares. To better understand the causes of post-traumatic stress disorder, it is necessary to integrate this biological dimension that sometimes precedes the triggering event.
Domestic violence and pandemic: under-documented causes of PTSD
The content available online remains largely focused on wars, natural disasters, and isolated assaults. However, two categories of causes have been clearly on the rise in recent years.
Intra-family violence and chronic exposure
Several studies published since 2022 describe a worrying increase in PTSD related to domestic and intra-family violence. Successive lockdowns, economic insecurity, and the rise in reports of violence have amplified the phenomenon. Unlike an accident or an isolated assault, repeated exposure establishes a state of permanent hypervigilance that weakens the same neurological circuits described above.
PTSD related to these violences often presents a more complex picture, with a combination of avoidance symptoms, dissociation, and mood disorders. Diagnosis may be delayed because the person remains in the traumatizing environment.
Impact of the COVID-19 pandemic
The pandemic has generated a documented wave of PTSD in previously less affected populations. Healthcare workers, patients hospitalized in intensive care, and grieving individuals are among the most affected groups, with an increase in diagnoses observed in several countries since 2020.
Post-intensive care PTSD is a particular case: the person has undergone invasive medical procedures in an altered state of consciousness, unable to integrate these experiences into a coherent narrative. The available data do not yet allow for measuring the exact extent of the phenomenon on a national scale, but clinical feedback is converging.
Risk factors for PTSD: why some people develop the disorder and others do not
In the face of the same event, the risk of developing PTSD depends on several interacting factors. Categorizing them helps identify prevention levers.
- Pre-existing individual factors: history of trauma (especially in childhood), prior anxiety or depressive disorders, social isolation at the time of the event. PTSD affects more women than men, according to WHO data.
- Characteristics of the event: the perceived threat to physical integrity, the duration of exposure, and the feeling of helplessness play a determining role. An event that provokes extreme feelings of fear and horror increases the risk.
- Post-event context: the absence of family or social support after the trauma is a well-documented aggravating factor. Conversely, feeling supported by one’s surroundings reduces the risk of PTSD, according to WHO.
These factors are not determinisms. A person with multiple vulnerabilities may go through a serious event without developing PTSD. Field reports vary on the relative weight of each factor, making individual prediction still difficult.
Structured therapeutic protocols: where do the treatment recommendations for PTSD stand
The most recent clinical guidelines emphasize standardized protocols, with defined durations and sequences. The recommended approaches share a common point: they focus on the trauma itself, not on general stress management.
- Trauma-focused cognitive-behavioral therapy (TF-CBT) works on restructuring thoughts related to the event and gradual exposure to traumatic memories.
- EMDR (eye movement desensitization and reprocessing) uses bilateral stimulation to facilitate the brain’s reprocessing of the traumatic memory.
- Prolonged exposure and Cognitive Processing Therapy (CPT) complement the arsenal with specific protocols according to the patient’s profile.
- Recent recommendations add lifestyle interventions: regular physical activity and sleep hygiene, in addition to psychotherapies.
Antidepressants may be prescribed in combination, but psychotherapy remains the cornerstone of treatment. The combination of several approaches, tailored to the individual’s profile, yields the best documented results to date.
PTSD remains a disorder for which the timing of care is as important as the method. An early diagnosis, made by a doctor or psychiatrist trained in psychotraumatology, allows for initiating a protocol before avoidance mechanisms become chronic. Research on epigenetic factors could eventually pave the way for targeted prevention strategies in the most exposed individuals.