Overview

What is post-traumatic stress disorder?

Post-Traumatic Stress Disorder (PTSD) is a mental health condition which is triggered by an individual experiencing or witnessing a traumatic event. It can cause ongoing emotional and psychological distress.

Common symptoms include:

• Anxiety, depression, or guilt
• Trouble sleeping or concentrating
• Flashbacks and nightmares
• Feeling on edge or easily startled
• Avoiding reminders of the trauma
• Substance use
• Irritability or aggression
• Physical stress responses like sweating or a rapid heartbeat

Mental health professionals assess and diagnose PTSD with criteria varying slightly between adults and children.¹

Causes

PTSD can develop from many types of trauma. Here are some of the most common causes:

Military 

PTSD is especially common among military personnel and veterans. Being exposed to intense, life-threatening situations such as combat, injury, or witnessing death can leave lasting emotional and mental scars. Factors before and after service, such as childhood trauma or poor coping skills can also increase the risk.² 

There are certain groups in the military that face even greater risk for developing PTSD:

• Women are more likely to experience sexual assault or harassment alongside combat stress 
• Ethnic minorities often face racism and discrimination also adding to the psychological stress. 
• Injured soldiers: Physical injuries can worsen PTSD symptoms and it can lead to long-term complications²

Prevalence 

• Around 7% of veterans are affected, compared to 6% of the general population.
• Among veterans, women are at higher risk, with 13% of female veterans developing PTSD versus 6% of males³ 

Women in the military

A study involving 750 female veterans found that many of them had experienced trauma during service:

• 22.5% faced sexual harassment
• 5.1% were sexually assaulted
• 22.7% experienced emotional bullying
• 3.3% faced physical assault

Those who were more at risk were younger women in officer roles or those involved in combat or support positions. These experienced were closely linked to PTSD, especially sexual assault and harassment, which has the greatest mental health impact.⁴ 

Racism and discrimination

Racial and ethnic minorities in the US military often experience discrimination:

• 31.2% of Black service members
• 23.3% of Asian Americans
• 21% of Hispanic personnel

Research has shown that discrimination can take a serious toll on both mental and physical health and it can increase the likelihood of risky behaviours such as heavy drinking.⁵ 

Combat injuries

Soldiers who suffer from physical war injuries during service are much more likely to develop PTSD, a study found that:

• 17% of injured soldiers met the criteria for PTSD
• Compared to just 3% of those who were not injured⁶

Sexual assault 

Sexual Assault is one of the leading causes of PTSD.

• Around 94% of rape or sexual assault survivors experience symptoms within the first two weeks
• 50% suffer long-term symptoms⁷ 

A study looking at PTSD after sexual assault found that:

• 75% of survivors met the criteria for PTSD within the first month
• 41% still did after a year
• Symptoms were severe early on but eased over time with the biggest improvements happening in the first three months.
• Researchers concluded that PTSD is a serious and common outcome of sexual assault, and the first three months are very important for healing⁸

Accidents 

Survivors of serious accidents like car accidents are at high risk for PTSD.

• A study showed that nearly 1 in 2 accident survivors can develop severe symptoms
• Many reported recurring nightmares, social struggles, and impaired work or school performance
• Factors like witnessing death, insomnia, or family issues can worsen the condition⁹ 
• Another study found 19% of car accident survivors who had injuries developed PTSD¹⁰ 

Natural disasters

Living through natural disasters like a tsunami, hurricane, earthquake or tornadoes can deeply impact the individual's mental health.

• PTSD rates vary between 5-60% for natural disasters and 25-75% for man-made disasters¹¹ 
• After Hurricane Katrina, PTSD cases had rose significantly from 12% to 21% in affected states¹²

Childhood abuse

Experiencing abuse during childhood is a strong predictor of PTSD later in life.

• About 1 in 4 children exposed to trauma develop PTSD by the age of 18
• Long-term effects often show up in adulthood and can worsen over time¹³ 

Nightmares and PTSD

Recurring nightmares are one of the most common and distressing symptoms of PTSD, which affects up to 72% of those diagnosed. These nightmares often replay the traumatic event and typically occur later during the night. People may wake up feeling intense fear or anxiety making it hard for them to fall back asleep which can lead to serious disruptions in sleep affecting their overall quality of life. Among veterans, 1 in 10 report trauma-induced nightmares, which are linked to severe mental health problems, higher suicide risk, and day-to-day difficulties such as struggling to function properly.^14,15 One study found that 60% of 500 active-duty U.S. military personnel had trauma-related nightmares.¹⁶ 

PTSD nightmares vs. regular nightmares

PTSD-related nightmares are different from regular nightmares in both cause and content. Regular nightmares, which affects around 2-5% of people, are distressing dreams that wake someone up and are usually triggered by things such as stress, illness, medication, or even watching a scary movie.¹⁴ 

In contrast, PTSD nightmares stem from a traumatic experience involving a real or perceived threat to a person’s safety. These dreams are often a repeat of the traumatic event or follow similar themes making them more intense and emotionally charged than the typical nightmares.¹⁵ 

Neurobiology

Role of the amygdala and hippocampus

Nightmares and PTSD are closely linked to the changes in the brain’s fear and memory systems, especially the amygdala and hippocampus. The Amygdala processes emotions like fear and helps detect danger whilst the Hippocampus stores and organises memories, including time, place and details.In PTSD, they can become overactive or not function properly. Some clinical studies have shown that stress can affect how memory works causing changes in brain areas such as the amygdala, hippocampus, and the medial prefrontal cortex.¹⁸ 

In a study, brain scans were done on combat veterans with and without PTSD while they viewed trauma-related and neutral images; they participated in a memory test a week later on what they remembered. 

Veterans with PTSD showed reduced activity in both the amygdala and hippocampus while encoding traumatic memories. When the trauma was emotionally intense, the hippocampus responded even less, this was linked to higher PTSD symptoms. The PTSD participants also had more false memories, remembering the general idea of the event but missing key details. 

This suggests that memories were stored without enough context, which leads to confusion, the common features of PTSD. These poorly stored memories often reappear in nightmares, which feel vivid but lack clarity. The amygdala’s intense emotional response, paired with poor memory encoding, may explain why nightmares in PTSD are so emotionally overwhelming and repetitive.¹⁷ 

REM sleep disruption

Rapid Eye Movement (REM) sleep (when most dreaming happens) is important for processing emotions and memories. PTSD often causes fragmented REM sleep which disrupts emotional healing overnight which can lead to poor sleep, ongoing negative thinking, and more frequent nightmares. These REM-related nightmares are highly distressing and linked to worse mental health and increased suicide risk. Poor REM sleep may also contribute to the development and persistence of PTSD.¹⁹

HPA axis and stress response

The Hypothalamic-Pituitary-Adrenal (HPA) axis controls how the body responds to stress. In PTSD, this system can become dysregulated due to the trauma. One study found that veterans with PTSD experienced more awakenings during sleep and higher activation of the sympathetic nervous system (the body’s fight or flight mode), making sleeping even harder.²⁰ 

How nightmares impact PTSD and daily life

Daytime PTSD symptoms

People with PTSD often struggle during the day due to poor or disrupted sleep, especially nightmares. Around 80-90% report insomnia, and 50-70% experience frequent nightmares, which can lead to increased anxiety, stress, anger, exhaustion, and issues like difficulty concentrating, intrusive thoughts, and hypervigilance.²¹ 

A study found that when PTSD sufferers had worse sleep, their daytime symptoms also worsened. Women, in particular, were the most affected by poor sleep quality and took longer to fall asleep, which led to more severe symptoms the next day. Interestingly, symptom relief was linked not just to longer sleep, but to having less distressing nightmares.²² 

Quality of life

PTSD can affect someone’s daily functioning and overall happiness. Key effects include: 

• Sleep problems: Tiredness, low energy, and poor focus 
• Mental health: Increased anxiety, depression, and stress
• Social and occupational impairment: Struggles with family, friends, and work
• Suicidal risk: Severe symptoms can increase suicidal thoughts
• Emotional dysregulation: Difficulty managing feelings
• Overall well-being: A noticeable drop in life satisfaction and well-being

Treatment 

Cognitive-behavioral therapy for insomnia (CBT-I)

CBT-I helps improve sleep by changing unhelpful sleeping habits and thought patterns in PTSD patients; it's often used alongside IRT. In study of 40 combat veterans, those who received four sessions of CBT-I (with optional IRT) showed better sleep, fewer PTSD symptoms, and reduced depression.²³ 

Imagery rehearsal therapy (IRT)

IRT is a technique used to rewrite nightmares with a more positive outcome to reduce how often it happens and its emotional impact. A study involving sexual assault survivors with PTSD, used CBT alone or CBT with IRT led to fewer PTSD symptoms and better mental health. Targeting nightmares early in treatment was helpful for those most affected by them.²⁴ 

Medication

Medications such as Prazosin should only be used under medical supervision. Research suggests that Prazosin effectively reduces PTSD nightmares by lowering norepinephrine levels.²⁵

Summary

Nightmares are not just a symptom but they are known to actively worsen PTSD. Treating it early can help improve sleep, and overall quality of life. Ignoring it may make PTSD harder to manage long-term.