Several new studies focusing on sex differences in pain and addiction suggest that females could be more susceptible to drug addiction and addiction-like behaviours than males. Researchers also investigated how sleep deprivation affected the likelihood of relapse, partly driven by hormone differences in females and males. The studies will be presented at the American Physiological Society’s seventh conference on New Trends in Sex and Gender Medicine from 19 to 22 October.
This study used a rat model to investigate the connection between opioid abstinence and persistent sleep loss and its impact on the body’s central stress response system. Researchers specifically found persistent sleep disruption may cause or perpetuate abnormalities in their hypothalamic-pituitary adrenal axis. These abnormalities increase the risk of vulnerability to relapse during oxycodone abstinence in some individuals. Scientists are now working to identify susceptibility factors that play a role in boosting the risk of relapse. Adequate sleep may be critical for successful recovery from opioid addiction.
Researchers conducting this study explored how the opioid epidemic in the US continues and evolved during the ongoing COVID pandemic. Women have made up the majority of those prescribed opioids for pain treatment. Prescribed opioids for pain management became the primary conduit to abuse and addiction for women, and the researchers found that mitigations in opioid prescriptions have been followed by increases in the use of other substances, such as heroin and fentanyl, in both men and women. While the rate of opioid use and overdose is higher in men, women have a higher rate of overdose death. Understanding how opioid use and addiction differ in their effect on men and women is key to ending the epidemic.
A rat model was also used to evaluate sex differences in vulnerability to addiction. Their results indicate activation of a specific subset of receptors for oestrogens enhances established cocaine-seeking behaviors in female rats. In male rats, the preference for cocaine under the same circumstances was reduced, involving the area of the brain linked to compulsive behaviours. Females show a greater response than males to stimulants such as amphetamine and cocaine in part due to the gonadal hormone oestradiol, which is one of the three forms of oestrogen. The hope is these results will lead to a better understanding of the mechanisms of addiction-related behaviors and the development of sex-specific treatments for addiction.
Source: American Physiological Society
