What is PTSD?

Post-traumatic stress disorder (PTSD) is a mental health condition that can develop after a person is involved in or witnesses a traumatic event. Traumatic events are severely distressing experiences that involve death or threaten a person’s life, e.g. a car accident or violent assault.

It is natural to experience emotional distress after trauma; in most cases, people start to recover in the days or weeks after the event. However, a person with PTSD will have distressing symptoms that last for more than four weeks and make it difficult to return to normal daily activities. Symptoms of PTSD include nightmares, upsetting memories and negative changes in behaviour and emotions.


The most common types of trauma which can cause PTSD include:

  • Sexual assault, e.g. rape, childhood sexual abuse
  • Serious accidents, e.g. car crash
  • Violence, e.g. domestic violence, mugging, kidnapping
  • Exposure to war zones, e.g. witnessing death or serious injury, participating in combat
  • Natural disasters, e.g. earthquake, hurricane
  • Sudden, unexpected death or life-threatening illness of a loved one
  • Medical events, e.g. heart attack, stroke, treatment in a hospital’s intensive care unit

Not everyone experiences trauma will get PTSD. Doctors do not yet understand why some people are more likely to get PTSD than others.


Symptoms of PTSD can start right after the traumatic event, or they can take months or years to appear. People with PTSD have symptoms that last more than four weeks. Symptoms may come and go; they often get worse when a person is under stress.

PTSD can make a person feel as if they are experiencing trauma again and again through thoughts and feelings. People with PTSD may have:

  • Repeated nightmares about the traumatic event
  • Intrusive upsetting memories of the traumatic event
  • Flashbacks - feeling or acting as if the trauma is happening again (this may include hallucinations)
  • Intense distress when reminded of the trauma
  • A physical response to reminders of the trauma, e.g. sweating, palpitations

People with PTSD try to avoid anything that reminds them of the traumatic event. They may:

  • Avoid memories, thoughts and feelings related to the trauma
  • Avoid activities, places, objects, conversations or people that remind them of the trauma
  • Lose memories of important aspects of the trauma
  • Lose interest in activities they used to enjoy
  • Feel detached from other people
  • Be unable to experience positive emotions e.g. feelings of love, happiness or satisfaction
  • Have ongoing negative emotions, e.g. fear, horror, anger, guilt, or shame.
  • Have a negative outlook on life

People with PTSD also have negative changes in their behaviour and emotions, such as:

  • Difficulty sleeping
  • Irritable moods or outbursts of anger
  • Reckless or self-destructive behaviour
  • Difficulty concentrating
  • Overly sensitive to surroundings
  • Startling easily

PTSD symptoms can make it difficult for a person to work, maintain relationships and carry out regular day-to-day activities.

People with PTSD are at higher risk of developing other health problems such as nervous system, cardiovascular and respiratory diseases. This is most likely due to inflammatory processes.

People with PTSD are more likely to have other mental health issues such as depression and anxiety and may be at higher risk of attempting suicide.

Some people turn to substance abuse to relieve their PTSD symptoms. This can lead to dependence on alcohol or illicit drugs.

Established Treatments

The goal of treatment is to decrease symptoms of PTSD. Doctors use medication and psychotherapy to treat PTSD. People respond differently to medication and psychotherapy so doctors often need to switch or combine treatments to find one that works.

Medicines for PTSD

Doctors usually treat PTSD with antidepressants, such as:

  • Citalopram
  • Escitalopram
  • Fluoxetine
  • Fluvoxamine
  • Paroxetine
  • Sertraline
  • Mirtazapine
  • Amitriptyline
  • Phenelzine

Different types of psychotherapy such as cognitive-behavioural therapy (CBT) can help people with PTSD by:

  • Changing problematic behaviour
  • Reducing distressing thought patterns
  • Changing emotional responses
  • Teaching coping skills

Sometimes therapists treat PTSD by intentionally exposing a person to the source of anxiety in a safe environment to help them overcome their distress.

Your doctor can provide more information about treatments for PTSD.

Treatment with Medical Cannabis

Medical Cannabis and Treatment of PTSD

The cannabis plant contains many compounds which affect the human body in different ways. Cannabinoids THC (Δ9-tetrahydrocannabinol) and CBD (cannabidiol) are the most abundant active compounds. THC is responsible for most of the mind-altering effects of cannabis.

Researchers do not yet fully understand the role of cannabinoids in PTSD. It is thought that endocannabinoids - cannabinoids naturally produced in the human body - are involved in regulation of the fight-or-flight response, fear memory and related inflammatory processes.

One human study (Neumeister et al., 2013) indicated that changes in the endocannabinoid system - in particular, increased availability of the CB1 receptor - could play a role in PTSD.

Wilker et al. (2015) found that people with PTSD had lower concentrations of endocannabinoids than healthy volunteers using measurements taken from the hair of 76 people in total.

Although these studies do suggest a possible link between changes in the body’s own cannabinoids and PTSD, the significance of this change and how it relates to treatment with cannabis-based medicines is unknown.

The majority of research on this topic is preclinical in nature and relevance to human patients is uncertain. Almost all currently published studies looking at cannabis or cannabinoids in humans with PTSD do not meet the clinical trial gold standard of a double-blind, placebo controlled design. Findings are limited by small sample sizes, short duration, non-randomised participants, lack of adjustment for important factors which can alter results and lack of a control group.

  • The efficacy of nabilone, a synthetic cannabinoid, in the treatment of PTSD-associated nightmares: A preliminary randomized, double-blind, placebo-controlled cross-over design study
    This study compared the effect of nabilone - a man-made cannabinoid similar to THC - with a placebo for treating nightmares from PTSD. This was a double-blind trial which means that neither patients nor staff knew which treatment was given.

    19 Canadian male military personnel with PTSD who continued to have trauma-related nightmares despite standard treatment were divided into two groups and given either nabilone or a placebo for seven weeks. After that, treatment was stopped for a two-week washout period and then the groups were given the opposite treatment for seven weeks.

    Results found that the groups experienced a statistically significant reduction in nightmares while receiving nabilone in comparison with placebo. Neither group experienced severe adverse events.

Long term effects of cannabis usage and interactions with other medicines are not yet fully understood. Large scale trials of longer duration are needed before any conclusions can be drawn on the use of cannabis-based medicines in PTSD.

References available at end of page.

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Related Advocacy Groups

There are several organizations in Australia which provide information and support to people with PTSD and their families. Below are links to their websites:

Beyond Blue

Black Dog Institute

SANE Australia

Phoenix Australia