PTSD Causes, Risk Factors, Signs & Symptoms

PTSD can develop when someone experiences, sees or learns about an event involving actual or threatened death, serious injury or sexual violence.


It is believed that PTSD is caused by a complex mix of:

  • Life experiences, including the amount and severity of trauma you have experienced since early childhood.
  • The way your brain regulates the chemicals and hormones your body releases in response to stress.
  • Inherited mental health risks such as an increased risk of anxiety or depression and inherited aspects of your personality or temperament.

Risk Factors

  • Having a job that increases your risk of being exposed to traumatic events, such as first responders, corrections and military personnel.
  • Experiencing intense or long-lasting trauma.
  • Feeling horror, helplessness or extreme fear.
  • Seeing people get killed or hurt.
  • Having experienced other trauma earlier in life, including childhood abuse and or neglect.
  • Having other metal health problems such as anxiety or depression.
  • Lacking a good support system of family and friends.
  • Dealing with extra stress after the event, such as loss of a loved one, pain and injury, or loss of a job or home.
  • Having biological (blood) relatives with mental health problems including PTSD or depression.

PTSD can increase the risk of other mental health problems such as:

  • Depression and anxiety,
  • Issues with alcohol and drug use,
  • Suicidal thoughts and behaviours.

Signs and Symptoms

Symptoms often start within 1 month of an event or repeated events. In some cases, symptoms may not appear until months or years later. The symptoms can make it hard for the person to live their everyday life and can be accompanied by depression, substance abuse, or other anxiety disorders. Below are 3 types of symptoms associated with PTSD1:

Intrusive Memories

Also called re-experiencing symptoms, these memories can start from the persons own thoughts, or can be triggered by words, object or situations that are reminders of the traumatic event. Intrusive memories include:

  • Recurring, unwanted distressing memories of the traumatic event
  • reliving the event as if it were happening again,
  • Upsetting dreams about the event, and
  • Severe emotional distress or physical reactions (heart racing, hands sweating) to something that reminds you of the event.


Avoidance symptoms may cause a person to change their routine, including avoiding things that remind them of the event as well as negative changes in thinking and moods. This includes:

  • Trying to avoid thinking about the event,
  • Avoiding places, objects, activities or people that remind you of the event,
  • Increased negative feelings about self or others,
  • Feeling emotionally numb or inability to experience positive or negative emotions,
  • Feeling hopeless about the future,
  • Losing interest in activities that were enjoyable in the past,
  • Feeling strong guilt, depression or worry,
  • Memory problems including not remembering important aspects of the traumatic event,
  • Difficulty maintaining close relationships.

Hyper-arousal Symptoms

These symptoms are changes in emotional reactions usually constant and can make a person feel stressed, angry, overwhelmed and “on guard.” The symptoms include:

  • Irritability, feeling tense or “on guard,”
  • Difficulty sleeping,
  • Angry outbursts or aggressive behaviours,
  • Being on constant guard for danger,
  • Feelings of overwhelming guilt or shame,
  • Self-destructive behaviours,
  • Trouble concentrating or sleeping, and
  • Being easily startled or frightened.

Learn how to respond to signs and symptoms in a worker.

When to see a Psychologist or Physician

A person should see a Psychologist or Physician if the symptoms last for more than one month and include experiencing at least:2

  • one intrusive memory symptom
  • three avoidance symptoms and
  • two hyper-arousal symptoms

Learn how to find a psychologist.


The Canadian Institute for Public Safety Research and Treatment (CIPSRT) has additional screening tools available including Anxiety, Depression, Stress, Panic Disorder, Risky Alcohol Use and Social Anxiety Disorder. These tools are anonymous and help to identify symptoms. They are intended to help increase awareness and educate and are not designed to provide a clinical diagnosis.

The results let you compare your responses to previously published responses from the general population or other public safety personnel. Your responses are not recorded and there is no person monitoring the screening tools to provide support. If you need assistance you can anonymously email your results to yourself and take that information to an appropriate healthcare provider such as a psychologist or Physician. To access these screening tools:

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Are You Looking for Confidential Peer Support?

Boots on the Ground provide confidential, caring and compassionate Peer Support to First Responders across the Province of Ontario. To access this support call this toll free number: 1-833-677-2668

For more information:

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PTSD and Anti-Stigma Awareness eLearning

This eLearning course serves as a foundation for those individuals and organizations who are looking to create awareness and a common understanding throughout their organizations. It also provides important information on:

  • How having PTSD may impact how someone may react at work
  • Understand common triggers for PTSD
  • Highlights how stigma can impact someone who is experiencing PTSD
  • Reinforces the importance of early treatment
  • Steps that workers or supervisors can take to talk to someone who is showing signs of PTSD
  • Techniques that can be used to manage stress, manage signs and symptoms and take care of yourself
View eLearning

Suicide Prevention Healthcare Modules – MHCC

These modules will help the healthcare professionals to:

  • Evaluate the level of risk for suicide and determine how best to intervene.
  • Understand the prevalence of, and which groups are at high-risk for suicide in Canada.
  • Build trust with your patient and gain the confidence needed to have a conversation with a patient about suicide.
  • Understand some of the tools and resources available to support the identification of the risk of suicide among your patients, and how to better offer that follow-up support.
View Modules

What PTSD Might Look Like at Work

PTSD At Work

Each individual will have their own responses and coping skills in reaction to traumatic events, but there are some identified examples of how PTSD may manifest at work, including:

  • Trouble remembering or concentrating on tasks,
  • Difficulty managing time or completing tasks,
  • Feelings of fear and anxiety with usual duties,
  • Unreasonable reactions to normal situations,
  • Anger outbursts and interpersonal conflict,
  • Excessive fatigue and abnormal sleep patterns,
  • Inability to cope with stressful events,
  • Avoiding certain job duties previously performed,
  • Social withdrawal,
  • Increased alcohol use after work,
  • Performance deterioration,
  • Lateness or absenteeism.

Do I have PTSD?


Understanding the Legal Requirements

Under the Occupational Health and Safety Act employers and supervisors are required to take every reasonable precaution to protect workers from harm. They are also required to inform all workers about psychological hazards on the job and train employees how to prevent these hazards and protect themselves. Workers are required to follow policies and procedures set out by the employer.

Learn more about the legislative requirements for Recovery & Return to Work.

Developing Policies & Procedures

Policies and procedures related to address PTSD should align with any existing mental health and wellness program and the organizational values. When you are Just Getting Started the policies and procedures you want to consider developing include:

Organizational PTSD Policy

Sample Organizational Policy

Anti-stigma Policy and Procedure

Sample Anti-Stigma Policy

Recovery and Return to Work Policy

Sample Return to Work Policy

Hazard and Incident Reporting Policy

Sample Reporting Policy

Developing a Policy Statement

A policy statement outlines the organizations commitment to addressing Post Traumatic Stress Disorder in the workplace and support of the Workers. Ideally it should be signed and dated by the Organizational Leaders.

It should include a statements that outline:

  • Policies, procedures and programs will be established to address PTSD in the workplace.
  • The organization will commit to providing psychological support in line with emerging best practices, or that are known to be effective, to its workers and, in particular, senior leadership support is demonstrated.
  • The organization will commit required resources to establish, implement and maintain the Prevention Plan & Program.
  • Worker participation is important and required in the development, implementation and improvement of the PTSD Prevention Plan & Program.
  • Focus on organizational needs, understand how PTSD fits into the overall workplace psychological health.
  • How the policy will contribute to a mentally healthy and psychological safe workplace.

1. Mayo Clinic, 2016. National Institute of Mental Health, 2016.
2. National Institute of Mental Health, 2016.
3. Great West Life Centre for Mental Health in the Workplace, 2005.