PTSD starts with experiencing trauma. It is characterized by four symptom clusters: intrusion (re-experiencing), persistent avoidance, negative changes in cognition and mood, and alterations in aurousal and reactivity.^1,5 The most common cause of PTSD is the unexpected death of a loved one,¹ although there can be many possible causes, such as exposure to sexual violence, war, physical assault, a natural disaster, or a vehicle accident.² A person may develop PTSD after experiencing the trauma themselves, witnessing it, or even learning about a trauma that affected a close relative or friend.²

PTSD is a serious and under-treated condition, which can occur at any age, and can have a negative effect on many social and economic aspects of people’s lives.^2-4

PTSD can be characterized into four symptom clusters:⁵

• Intrusion (Re-experiencing the trauma) – recurrent memories, nightmares, and flashbacks.
  
• Persistent avoidance – avoiding thoughts, feelings, objects, people, or places that are associated with the trauma.
  
• Negative cognition and mood – exaggerated negative beliefs about oneself or the world, shame or guilt, reduced emotion, feeling alienated, and difficulty remembering details of the trauma.
  
• Alterations in arousal and reactivity – irritability, being in a state of high alert, reckless behavior, sleep disturbance, and difficulty concentrating.
  

Symptoms of PTSD vary from person to person. Some people may predominantly experience one of the four symptom types, whereas others may experience a combination of symptoms.² The timing of symptoms may also vary – most people with PTSD experience symptoms immediately after the traumatic event,³ whereas, in others, there may be a delay of months or even years before symptoms develop.²

Worldwide, most people (70%) will experience a traumatic event in their lifetime.⁶ Although the majority of people exposed to trauma recover normally, approximately 5.6% of those exposed will develop PTSD.³ This equates to about 3.9% of all people experiencing PTSD in their lifetime.³ Approximately 13 million adults in the US are estimated to have PTSD.^{11, 12, 13}

PTSD is more than twice as common in women than in men. Rates of PTSD are higher among veterans and others whose job increases the risk of exposure to trauma (e.g., police, firefighters, and emergency medical personnel).²

Some people with PTSD recover quickly, while others may have symptoms for many years.² PTSD can have negative consequences in many aspects of people’s lives, including intimate relationships, friendships and socializing, parenting, finances, and work and academic performance.⁴

A global survey by the World Health Organization (WHO) found that people with PTSD miss an average of 15 additional days of work or activities per year, compared with people without PTSD,⁷ which can lead to substantial costs. In older people, symptoms of PTSD may be exacerbated by declining health, reduced cognitive abilities, and social isolation, adding to the burden of the disorder.²

People who are concerned that they – or their loved ones – are experiencing symptoms of PTSD should see their doctor for help and advice. PTSD is diagnosed using interviews with the patient, or with parents for young children.² Symptoms of PTSD are often similar to symptoms of other disorders (such as depression), which can lead to underdiagnosis or misdiagnosis of PTSD.⁸

Treatment of PTSD usually involves psychotherapy – tailored behavioral and emotional support from professionals – and may involve medication.⁹ However, a review of global data suggests that fewer than 50% of people with PTSD seek treatment.³ Furthermore, a delay in starting treatment can lead to worse outcomes.¹⁰ Early diagnosis and treatment are essential for people with PTSD.