People who’ve experienced childhood trauma get a more pleasurable “high” from morphine and other such opioids, new research suggests.
University of Exeter scientists compared the effects of morphine on 52 healthy people, broken down into the following two groups:
- 27 with a history of childhood abuse and neglect
- 25 who reported no such experiences in childhood
Those with childhood trauma liked morphine (an opioid drug) more, felt more euphoric effects and had a stronger desire for further doses after their initial dose. Those with no childhood trauma were more likely to dislike the effects, feel dizzy, nauseous or experience other negative side effects.
There are high rates of childhood trauma in people with addictions. Our findings show that these sorts of experiences can actually change how certain drugs feel.Dr Molly Carlyle, Researcher at Exeter University/University Of Queensland
To our knowledge, this is the first study to link childhood trauma with the effects of opioids in people without a history of addiction, suggesting that childhood trauma may lead to a greater sensitivity to the positive and pleasurable effects of opioids.
This may explain the link between childhood trauma and a vulnerability to an opioid use disorder (OUD), with implications for treatments and the prescribing of opioids medically.
One possible explanation for the differing responses to morphine is that childhood trauma affects the development of the endogenous opioid system, a pain-relieving system that is sensitive to chemicals including endorphins – our natural opioids.
“It’s possible that childhood trauma dampens that system,” Carlyle explained.
When a baby cries and is comforted, endorphins are released – so if loving interactions like this don’t happen, this system may develop differently and could become more sensitive to the rewarding effects of opioid based drugs.
Professor Celia Morgan, of the University of Exeter, who leads the research group said
Our findings that people who have been traumatised as children are more likely to enjoy morphine might help to reduce stigma around heroin use.Professor Celia Morgan, of the University of Exeter
“Many opioid addicts are people who were directly or indirectly traumatised in early childhood, but it is still widely believed that addiction is a weakness, moral failing and that addicts simply lack self-control, motivation and are somehow less worthy and valuable within our society compared to others, which we know simply isn’t true.
“This research may be a step towards treating heroin addicts with more compassion, as we would children with histories of trauma.
Our study also highlights the importance of interventions aimed at high-risk children and adolescents to protect against opioid use.
The study’s participants were aged between 18-65 years old, had either reported experiencing severe childhood trauma (abuse or neglect, as measured by the Childhood Trauma Questionnaire) or reported no childhood trauma.
They each attended two sessions, a week apart and received either an active dose of morphine (0.15mg/kg) or a negligible control dose (0.01mg/kg) in a randomised, double-blind crossover design.
People’s experiences of morphine were measured by asking them a set of questions eight times – once before the morphine injections, then at regular intervals afterwards.
Pain was also measured by placing a hand in cold water and recording how long it took people to find this painful and how long they could tolerate leaving their hand in the water.
Morphine increased the participants pain threshold and tolerance, but this did not differ between the trauma and non-trauma groups.
There was also a computerised button-pressing task that measured effort to obtain more morphine by button pressing for either a theoretical amount of money or morphine. No differences were found between the two groups during this task. This may have been because money is highly rewarding in non-addicted groups and was not a suitable comparator for this task.
The testing was carried out at the Clinical Research Facility at the Royal Devon and Exeter Hospital. You can learn more about the trial, it’s clinical findings, research methods by clicking here.