Trauma has been a part of the human experience for millennia and our responses to trauma are adaptive. If we didn’t recognize a traumatic experience as dangerous we wouldn’t know to avoid it in the future. The ability to avoid trauma is the ability to stay alive, particularly in earlier points in human evolution. In our modern world, many of the traumatic experiences people have can be triggered by relatively benign external cues. They can have responses that trigger a fight or flight response, designed to keep them alive even when there is no threat.
This hyperreactivity and hypervigilance is a hallmark of trauma-related disorders, particularly Post Traumatic Stress Disorder. PTSD is the most rigidly defined trauma-related disorder in DSM-5, although it is not the only way one can experience trauma as an ongoing impairment. PTSD is well defined and that makes it relatively easy to research, which is why we have the most data about that particular kind of impairment.
Traumatic experiences prepare us to run away or fight to save our lives should we encounter information from our environment that makes us suspect that trauma could reoccur. Whenever we get the signal that danger may be close, our autonomic nervous system kicks into high gear and we are ready to fight, run, or freeze. This was a very helpful response in an era of tigers on the Serengeti, but with loud noises like a car starting or a door slamming, it can lead to lots of fight or flight responses when there are no adaptive qualities.
What we mean by disorder in the term post-traumatic stress disorder is that the body gets ready for action when there is no useful action to be taken. The readiness generated does not help the situation and likely gets in the way of people who experience it on a day-to-day basis.
When looking at substance use disorders, we see people using substances that will provide various immediate stimulation to their brain. However, all of these substance use disorders share a few key components, usually dopamine. The pleasure and reward compound in our brain is released. Other neurotransmitters may be released and in quantities, greater than usual in our day-to-day lives. These can include endogenous chemicals that bind to opioid receptors and reduce pain and other related effects.
No drugs of abuse would do anything if our brains were not ready to receive those signals. The overlap between our brains and these substances is that we were built to respond to reward. The relaxation, alertness, pleasure, or reduced physical or emotional pain we experience from substances of abuse are all based on naturally occurring systems in our brain that help to keep us alive and encourage us to do the right things. The trick with substances of abuse is that substances allow us to take a shortcut to those experiences without having to do the activities that would generally release those compounds in our brains.
You don’t need to accomplish something that makes you feel really good about yourself if you have a drug that will do that for you without having to go through any of the hassles of accomplishing things in the first place.
When looking at the combined effects of traumatic experiences and substance use disorders, we routinely find across many studies that up to 95% of people reporting for help with substance use disorders have had exposure to traumatic experiences. In the general population, up to 75% of individuals with a substance use disorder have experienced trauma at some point in their lives. Similarly, when we look at people who have experienced substance use disorders, and the kinds of trauma that have impacted them, we see that early childhood trauma predisposes people to have worse experiences with substance use disorders. These include earlier first intoxication, more severe substance use, a greater number of drugs used in a lifetime, higher severity of dependence, and a greater number of treatment episodes.
Substance use disorders that come along with PTSD are worse than those that do not and when childhood trauma is present, we expect there to be more severe and chronic use of both substances and as well as traumatic experiences.
Since PTSD helps our brains adapt to survive in dangerous contexts and substances of abuse act on those very same brain systems to soothe our pain or increase our sense of well being in the short term, the brain-based explanation for why people with trauma would be drawn to substances of abuse makes perfect sense.
Those substances make brains feel better, experience less pain, and in the short term, may have relief from the symptoms of fear and chronic hypervigilance that they are experiencing as a result of their trauma.
Given the difficulty of accessing effective treatments for PTSD and the relative ease with which people can obtain substances of abuse, it makes sense that people with PTSD would find substances of abuse to be helpful in the short term.
The tragedy is that the use of these substances creates yet more health and mental health problems and often further impairs the lives of people who, through no fault of their own, were exposed to traumatic experiences in the first place. The assessment and treatment of trauma, particularly early trauma, is a highly likely way to reduce the burden of substance use disorders later in life. It is a compelling case for designing interventions that work. More research is needed to understand the connections between these conditions but taking them seriously makes all the sense in the world.
