PTSD risk factors: why some people develop it after trauma

What PTSD is

It is natural to feel afraid during and after a traumatic situation, and most people recover from their symptoms over time. Those who keep having symptoms may be diagnosed with PTSD (NIMH). The traumatic event may be life-threatening, such as combat, a natural disaster, a car accident or sexual assault, but it does not have to be dangerous: the sudden, unexpected death of a loved one can also cause PTSD (MedlinePlus). People with PTSD feel stressed or frightened long after the trauma is over, even when they are no longer in danger (MedlinePlus) (NIMH).

Anyone can develop PTSD at any age. This includes combat veterans and people who have experienced or witnessed a physical or sexual assault, abuse, an accident, a disaster, a terror attack or other serious events. Sometimes, learning that a relative or close friend went through trauma can cause PTSD (NIMH).

NIMH cites the National Center for PTSD, a U.S. Department of Veterans Affairs program: about 6 of every 100 people will have PTSD at some point in their lifetime (NIMH). There is no score or calculator on this page; the factors below are the ones NIMH and MedlinePlus name.

Who is more likely to develop PTSD

Not everyone who lives through a dangerous event develops PTSD. Some factors are present before the trauma; others play a role during and after it (NIMH). Researchers do not know why some people get PTSD and others do not; genetics, neurobiology, risk factors and personal factors may all play a part (MedlinePlus). Risk factors named by NIMH and MedlinePlus (NIMH) (MedlinePlus):

• Earlier trauma, especially in childhood. Exposure to previous traumatic experiences, particularly during childhood (NIMH).
• Being hurt, or seeing others hurt or killed during the event (NIMH).
• Feeling horror, helplessness or extreme fear (NIMH) (MedlinePlus).
• A traumatic event that lasts a long time (MedlinePlus).
• Little or no social support after the event (NIMH).
• Extra stress after the event, such as the loss of a loved one, pain and injury, or the loss of a job or home (NIMH).
• A personal or family history of mental illness or substance use (NIMH).
• Sex. Women are more likely than men to develop PTSD (NIMH) (MedlinePlus).

Certain aspects of the traumatic event and biological factors, such as genes, may also make some people more likely to develop PTSD (NIMH).

Resilience factors that may lower the chance

NIMH and MedlinePlus list resilience factors that may reduce the likelihood of PTSD (NIMH) (MedlinePlus):

• seeking out and getting support from friends, family or a support group;
• learning to feel okay about your own actions in response to the traumatic event;
• having a coping strategy for getting through the event and learning from it;
• being prepared and able to respond to upsetting events as they happen, despite feeling fear.

Signs and symptoms

Symptoms usually begin within 3 months of the traumatic event, but they sometimes appear later (NIMH), even months or years later, and they may come and go over many years (MedlinePlus). There are four types of symptoms (NIMH) (MedlinePlus):

• Re-experiencing: flashbacks (reliving the event, including physical symptoms such as a racing heart or sweating), recurring memories or dreams about the event, and distressing thoughts.
• Avoidance: staying away from places, events or objects that are reminders of the experience, and avoiding thoughts or feelings about the event. For example, some people avoid driving after a serious car accident.
• Arousal and reactivity: being easily startled, feeling tense or on edge, trouble concentrating or sleeping, angry outbursts, and risky or reckless behavior.
• Cognition and mood: trouble remembering key parts of the event, negative thoughts about yourself or the world, exaggerated blame or guilt, loss of interest in activities, and feeling cut off from others.

In children younger than 6, symptoms can include wetting the bed after having learned to use the toilet, forgetting how to talk or being unable to talk, acting out the scary event during play, and being unusually clingy with a parent or other adult. Older children and teens usually have symptoms more like those of adults (NIMH).

How PTSD is diagnosed

A mental health professional, such as a psychiatrist, psychologist or clinical social worker, can determine whether symptoms meet the criteria for PTSD (NIMH). An adult must have all of the following for at least 1 month: at least one re-experiencing symptom, at least one avoidance symptom, at least two arousal and reactivity symptoms, and at least two cognition and mood symptoms (NIMH). The symptoms must be severe enough to interfere with daily life, such as relationships or work, and must not be caused by medication, substance use or another illness (NIMH).

Some people recover within 6 months, while others have symptoms for a year or longer. People with PTSD often have other conditions too, such as depression, substance use, or one or more anxiety disorders (NIMH). See depression risk factors and anxiety risk factors.

Treatment and getting help

You can get better with treatment. The main treatments are psychotherapy, medicines, or both, with a mental health professional who has experience treating PTSD (NIMH). The FDA has approved two selective serotonin reuptake inhibitors (SSRIs), a type of antidepressant, for treating PTSD (NIMH).

NIMH lists ways to help yourself: follow your treatment plan, do exercise, mindfulness or other activities that reduce stress, keep routines for meals, exercise and sleep, spend time with trusted friends or relatives, expect symptoms to improve gradually, and avoid alcohol and drugs (NIMH).

The 988 Lifeline is free and confidential and available 24/7 (988 Lifeline).

Related guide: OCD risk factors.

Common questions

Can you get PTSD without being in danger yourself?

Yes. Learning that a relative or close friend went through trauma can sometimes cause PTSD (NIMH), and so can the sudden, unexpected death of a loved one (MedlinePlus).

How long after trauma can PTSD start?

Usually within 3 months, but sometimes later (NIMH), even months or years after the event (MedlinePlus).

Can PTSD be prevented?

MedlinePlus says certain factors, known as resilience factors, can help reduce the risk, such as support from other people and having a coping strategy (MedlinePlus) (NIMH).