Childhood trauma raises opioid addiction risk by changing how the brain responds to opioids. In a new study, adults who had childhood trauma felt more pleasure after a dose of morphine than adults without it. The drug’s pain relief was the same. That stronger reward response helps explain the higher addiction risk.
Summary: People with opioid addiction often report more childhood trauma. But it is still unclear whether a hard childhood is truly a risk factor. The new study shows that people with childhood trauma have changed brain pathways. So they are more likely to feel pleasure after a dose of morphine than adults with no childhood trauma. The study also found that childhood trauma does not change how well opioids ease pain.
In the US, addiction to and misuse of legal drugs, and the deaths tied to them, now exceed abuse of illegal drugs. Studies show that in 2019, more than 50,000 people died of opioid overdose. What is alarming is that almost one-third of all people prescribed opioids for pain tend to misuse them1.
Still, two-thirds of people never seem to misuse opioids, even with long use. So there must be some difference between those who misuse and those who do not. It may have something to do with hard experiences in childhood.
These findings show why opioid addiction treatment must target both the physical and mental factors behind addiction. That is especially true for people with a history of childhood hardship.
Many studies have shown that even minor childhood trauma may change how the brain responds to stress. For example, children who got less attention are at higher risk of anxiety as adults. After early trauma, the brain responds quite differently to stress for the rest of life2.
Earlier studies have shown that people addicted to drugs are more likely to have been mistreated or abused as children. Many studies also compared people addicted to various substances with healthy adults. Most show more severe childhood trauma in those addicted to substances3.
Does childhood trauma change how the brain responds to opioids?
This study was different because it was done in 52 healthy adults. None of them was addicted to opioids. Researchers split them into two groups. The first group had 27 people with a history of severe childhood trauma. The second had 25 people with no childhood trauma4.
In the test, both groups got a shot of morphine. Then researchers used a well-known scale to measure the high, or pleasure, each person got from it. To their surprise, people with childhood trauma liked morphine much more than those without childhood trauma. Morphine was also more likely to cause nausea and dizziness in people without childhood trauma.
This study shows that childhood trauma changes the brain and changes how a person responds to opioids. People with a painful childhood are more likely to enjoy the high of opioids.
Researchers think this may come from changes that early trauma causes in the body’s own opioid system. This system responds to natural endorphins (the happiness hormones) and natural opioids. But in people with childhood trauma, this pathway is less sensitive. So high-dose morphine brings pleasure but not side effects.
In people with a happy childhood, the body’s own opioid system is very sensitive to endorphins and natural opioids. So they do not handle high doses of opioids like morphine well.
Interestingly, childhood trauma seems to change only the high, or the feeling of pleasure. It does not change how well morphine eases pain.
In the test, researchers also asked people in both groups to put their hands in cold water. They timed how long each person took to pull their hand out from the pain. There was not much difference between the two groups. So morphine’s painkilling action holds up and has no link to childhood trauma.
Frequently asked questions
Does childhood trauma cause addiction?
Childhood trauma raises the risk. People with opioid addiction report more childhood trauma. Studies comparing people addicted to substances with healthy adults find more severe childhood trauma in the addicted group. Early trauma changes how the brain responds to stress for life. It also changes the pathways that make opioids feel rewarding.
Why do some people get addicted to opioids and others don’t?
About one-third of people prescribed opioids for pain misuse them, while two-thirds never do, even with long use. Hard childhood experiences seem to be part of the difference. In the morphine study, adults with severe childhood trauma liked the drug much more. They also had less of the nausea and dizziness that put others off.
Does childhood trauma affect how well opioids relieve pain?
No. Trauma changed the high, not the pain relief. When both groups held their hands in cold water after morphine, they pulled them out at about the same time. Morphine’s painkilling action held up whether or not a person had a painful childhood. Only the pleasure and the side effects differed.
How does trauma affect addiction recovery?
Trauma changes the brain’s opioid system, so treatment has to deal with more than the drug. Opioid addiction treatment works best when it targets both the physical and the mental factors behind the addiction. That is especially true for people with a history of childhood hardship, because their brains respond to opioids differently from the start.
Related reading
Childhood Abuse and Poor Health in Adulthood · Childhood Obesity: What Parents Need to Know · Co-Prescribing Stimulants and Opioids: Overdose Risk
References
1. Opioid Overdose Crisis. National Institute on Drug Abuse. Published March 11, 2021. Accessed October 30, 2021. https://www.drugabuse.gov/drug-topics/opioids/opioid-overdose-crisis
2. Gabor Maté MD. Addiction: Childhood Trauma, Stress and the Biology of Addiction. Journal of Restorative Medicine. 2012;1(1):56-63. doi:10.14200/jrm.2012.1.1005
3. Garami J, Valikhani A, Parkes D, et al. Examining Perceived Stress, Childhood Trauma and Interpersonal Trauma in Individuals With Drug Addiction. Psychol Rep. 2019;122(2):433-450. doi:10.1177/0033294118764918
4. Carlyle M, Broomby R, Simpson G, et al. A randomised, double-blind study investigating the relationship between early childhood trauma and the rewarding effects of morphine. Addiction Biology. 2021;26(6):e13047. doi:10.1111/adb.13047