Stress Hormone Could Make the Brain 'Forget' Addiction

By Zachary Siegel 07/29/15

A new study out of Switzerland finds cortisol reduces cravings because it acts on memory.

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A recent study published in the journal Translational Psychiatry demonstrated that cortisol, a stress hormone, has the ability to reduce cravings in heroin-addicted patients. Interestingly, results show that cortisol potentially makes the brian “forget” that it’s addicted.

The unremarkable hallmark of heroin addiction is an intense craving for the drug. Newly detoxed addicts vigorously crave heroin; even patients on methadone and buprenorphine, medications that help opioid users stabilize, report cravings for heroin from time-to-time.

Stressful events and conditions have also been found to increase cravings and the subsequent risk of relapse. It’s known that cortisol is released during withdrawal syndrome in absence of opioids and when opiate drugs are reintroduced to one’s system, the presence of cortisol is reduced. This finding led researchers to further investigate the role of cortisol in addiction.

Researchers in the present study gave 29 patients undergoing heroin-assisted treatment (HAT) a cortisol tablet or placebo before receiving a dose of heroin. The patients who were given cortisol reported a 25% decrease in cravings. The reduced cravings, however, were only found in users receiving low doses (113–305 mg per day) of heroin. But the authors suggest that higher doses of cortisol may have a stronger effect where it meets higher doses of heroin.

The authors write, “We believe this is the first study to examine the acute effects of cortisol administration in a population of heroin-dependent patients in a controlled study design. It shows that a single administration of cortisol leads to reduced craving.”

A possible mechanism for the craving-reducing effect of cortisol in humans may be its effects on memory retrieval. Cortisol has been shown to reduce memory retrieval in rodents and healthy humans. There is also evidence that emotionally charged memories are particularly sensitive to the effects of cortisol on memory.

“There is evidence that glucocorticoids can also reduce the retrieval of aversive memory and enhance fear extinction in post-traumatic stress disorder and phobia,” the authors of the study wrote.

The next step, said the researchers, is to determine the role cortisol plays in relapse prevention in patients who are abstinent.

You can read the full study here via Nature.

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Zachary Siegel is a freelance journalist specializing in science, health and drug policy. His reporting has also appeared in Slate, The Daily Beast, Salon, Huffington Post, among others. He writes often about addiction, sometimes drawing from his own experience. You can find out more about Zachary on Linkedin or follow him on Twitter.