Summary: People living with opioid addiction often report a greater degree of childhood trauma. However, it is still unclear if adverse childhood experience is really a risk factor. The new study shows that those with childhood trauma have altered brain pathways. It means that they are more likely to experience pleasure after a dose of morphine when compared to adults with no childhood trauma. Further, the experimental study found that childhood trauma has no impact on the pain-relieving action of opioids.
In the US, addiction and misuse of legal drugs and related deaths have exceeded the abuse of illicit 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 abuse it1.
Nonetheless, two-thirds of people never seem to abuse opioids, even on prolonged use. So, it means that there must be some difference between individuals who abuse and those who do not. It seems that it may have to do something with adverse experiences during childhood.
These findings highlight the importance of targeted opioid addiction treatment strategies that address both the physical and psychological factors contributing to addiction, especially for those with a history of childhood adversity.
Numerous studies have shown that even minor childhood trauma may alter the brain’s responses to various stressors. For example, children who received less attention during childhood are at greater risk of developing anxiety during adulthood. In addition, during early trauma, the brain responds quite differently to stressors for the rest of life2.
Earlier studies have shown that those addicted to drugs are more likely to be individuals with childhood maltreatment or abuse. In addition, many studies compared individuals addicted to various substances to healthy adults. Most studies show the presence of greater severity of childhood trauma in those addicted to substances3.
The new experiment provides strong evidence that childhood trauma may alter responses to opioids
This study differs in the way that it was carried out in 52 healthy adults. None of them was addicted to opioids. Researchers divided them into two groups. The first group consisted of 27 individuals with a history of severe childhood trauma. The second group consisted of 25 individuals with no childhood trauma4.
In the experiment, both the groups were given an injection of morphine. Then researchers used a well-known scale to measure the feeling of high or pleasure each one got from morphine injection. To the researcher’s surprise, individuals with childhood trauma had a much greater liking for morphine compared to those who did not have any childhood trauma. Not only that, morphine was more likely to cause nausea and dizziness in those without childhood trauma.
This study shows that childhood trauma results in changes in the brain, which alters a person’s response towards opioids. Those with painful childhood are more likely to enjoy the euphoric effect of opioids.
Researchers think this difference could be due to changes caused in the endogenous opioid system by the early trauma. This system is also sensitive to natural endorphins (hormones of happiness) and natural opioids. However, in those with childhood trauma, this pathway is less sensitive. Thus, high-dose morphine causes pleasure but not side effects.
On the contrary, the endogenous opioid system is highly sensitive to endorphins and natural opioids in those with a happy childhood. Thus, they are not able to tolerate high doses of opioids like morphine well.
Interestingly enough, it seems that childhood trauma only alters the high or experience of pleasure. However, it does not have any impact on the pain-relieving properties of morphine.
In the experiment, researchers also asked individuals from both groups to submerge their hands in cold water. They noted how long it took for each individual to pull their hands out due to pain. They found that there was not much difference between the two groups. Thus, the painkilling action of morphine is preserved and has no association with childhood trauma.
References
1. Abuse NI on D. 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
