The Link Between Trauma and Substance Use

Does trauma, especially early childhood trauma, lead to issues with substance use? Not always. Does it increase the likelihood of someone developing issues with substance use? Absolutely.

For decades, scientists have been examining the connection between substance use and traumatic experiences. This link has become more widely recognized with the popularity of books on the topic such as In the Realm of Hungry Ghosts by Gabor Maté and The Body Keeps the Score by Bessel van der Kolk.

Understanding how traumatic experiences may cause people to develop unhealthy ways of dealing with stress can help you understand why some people turn to substances for relief.

The Centre for Addiction and Mental Health, one of the leading research hospitals for mental health and addiction in Canada, defines trauma as, “the lasting and challenging emotional response that a person can experience after living through a distressing event.”

It’s not uncommon for people to develop PTSD (Post Traumatic Stress Disorder) following traumatic events, in fact, studies suggest that up to 10% of the population in North America may be on the PTSD spectrum. According to the Canadian Centre on Substance Use and Addiction, over 30% of people who access supports and services for substance use self-identify a connection between their substance use and trauma.

Though trauma and substance use are intrinsically linked, it’s not the only cause of substance use issues, but rather a contributing factor (including others such as genetic predisposition, early childhood experiences, personality traits, mental illness, substance use in the family, and among peers, and early use.)

Substance use as a coping mechanism or way of self-medicating due to trauma

Trauma causes a wide range of symptoms that can have a devastating impact on all areas of someone’s life, including the ability to regulate emotions. It can make it hard for people to trust others and cause them to withdraw from social situations and even relationships. Trauma can also manifest as physical symptoms in the body, including physical discomfort, fatigue, sensory flashbacks, and nightmares.

Any of these signs or symptoms could make someone turn to substance use as a coping mechanism. So, it’s easy to see how a trauma survivor with a range of these symptoms might resort to alcohol or drugs as a method of self-medication. In The Body Keeps Score, van der Kolk explains that drugs and alcohol can provide the “perfect, albeit temporary, antidote to virtually any symptom of trauma.”

Trauma can cause a dysregulated stress response

“Long after a traumatic experience is over, it may be reactivated at the slightest hint of danger and mobilize disturbed brain circuits and secrete massive amounts of stress hormones. This precipitates unpleasant emotions, intense physical sensations, and impulsive and aggressive actions.”

Bessel van der Kolk, The Body Keeps the Score. 

The stress response is often discussed in relation to what psychologists call the “window of tolerance.” The window of tolerance is the zone in which someone can effectively manage their emotions and stress response. Someone who has experienced trauma will often have a very narrow window of tolerance, with stresses either catapulting them into “hyperarousal” (aka the Fight or Flight response) or sending them into “hyporarousal” (aka the Freeze response) which can lead to the body shutting down through disassociation and depersonalization.


Hyperarousal is one of the common symptoms of trauma, especially in people with PTSD. Often referred to as fight or flight mode, the typical stress response people have when presented with perceived danger usually includes an increased heart rate, quick breathing, and the release of stress hormones like adrenaline and cortisol. A stress response like this will usually dissipate and return to normal after the danger or threat has passed.

When someone has experienced trauma, and especially if the trauma was prolonged like ongoing abuse, war, or unsafe living conditions, it can result in a total dysregulation of the stress response and a chronic state of hyperarousal, anxiety, hypervigilance, and alertness. Trauma sufferers often come to feel that the only reprieve they get from this unpleasant state is with substance use, especially alcohol, benzodiazepines, opioids, and cannabis.

Hypoarousal leading to dissociation and depersonalization

Alternatively, trauma can cause people to have an under-reactive and under-stimulated stress response that’s opposite to hyperstimulation. In response to stress and a real or perceived threat or danger, they may find themselves disassociating (a feeling of “mental escape” or “switching off”) or depersonalizing (a sense that things around them are not real), leaving them feeling emotionless, indifferent, and disengaged.

When a person is going through a brief or extended traumatic event, disassociating or depersonalizing from the circumstance can be a helpful and effective survival and coping strategy, allowing them to feel physically and emotionally numb and detached when needed. But for someone who has lived through trauma, a trigger (for example, a car backfiring in the previous example that sent someone into hyperarousal) may send them into depersonalization or dissociation long after this stress response has been activated. In this case, someone might turn to stimulants such as cocaine, amphetamines or nicotine, to temporarily move out of a state of numbness and into a state of sensation, alertness, and arousal that they are no longer able to achieve on their own.

In each of these scenarios, trauma impairs the body’s capacity to manage stress, increasing the likelihood that a person may turn to substance use to either calm down when suffering from hyperarousal or to escape from a state of numbness when suffering dissociation and depersonalization.

Trauma and substance use as a self-perpetuating cycle

There may be a vicious cycle created by the connection between trauma and substance use. When someone uses substances to manage the effects of trauma, they can often expose themselves to additional traumatic experiences, which in the end, can lead to more substance use. For example, when someone is under the influence of substances, they are more likely to put themselves in dangerous situations, such as driving drunk, or not recognizing their own boundaries, all of which can lead to further trauma, and then increasing levels of substance use.

It can be challenging to break this cycle, and many typical addiction treatment programs can make the mistake of treating only the symptoms (substance use) instead of addressing the root cause of the symptoms, such as trauma.

Understanding the connection between trauma and substance use can help you better understand your own or a loved one’s substance use patterns and help you decide what kind of support you may need or want. Asking a therapy provider if the therapist or method is trauma-informed is always a good idea because it might be crucial to success.

Struggling with substance use? ALAViDA can help.

If you’d like to change your relationship with substances, ALAViDA provides a wide range of support options. Connect with our care team for a personalized program proven to reduce substance use or use our self-guided approach to go at your own pace. Support is accessed through our TRAiL platform and includes a wide range of resources to help you reach your goals, including iCBT modules (internet-based Cognitive Behavioral Therapy), notifications and tracking tools, and more. Access the ALAViDA TRAiL.