Women’s hormone cycles may be tied to higher addiction and relapse rates
New research may finally explain why women are statistically more at risk of drug addiction and more likely to relapse when in recovery.
According to a new report published in the journal Neuropsychopharmacology, women’s hormonal cycles may make them both more prone to develop an addiction when exposed to drugs and more likely to respond to relapse triggers.
Erin Calipari – assistant professor of pharmacology in the Vanderbilt University Center for Addiction Research – says the research is crucial because although women are known to be more vulnerable to drug addiction, most addiction studies have focused on men.
“Women becoming addicted to drugs may be a fundamentally different process than men,” Calipari said. “It’s important to understand this, because it’s the first step in developing treatments that are actually effective.”
First, Calipari set out to examine this issue by evaluating how hormones affect women’s minds. Specifically, she found that when fertility-related hormone levels are higher, females tend to learn faster, make stronger associations with triggers in their environment, and become more prone to seek rewards.
With this information in mind, Calipari hopes to eventually be able to develop medications that could override these effects on women’s brains. In the meantime, however, she says this information can be incredibly valuable in helping medical professionals educate women about their addiction and relapse risks. For example, she notes that women may be at higher risk of relapse when visiting a place where they have used drugs in the past.
As she explains in the report, past research using animals to assess addiction have avoided using female animals specifically so they don’t have to account for changes in hormonal cycles. Thus, nearly all medical research into addiction has relied entirely on male subjects. Calipari suggests this may also be why many women do not respond to the widely used medications or treatments for addiction.
To investigate this issue, Calipari created a test where male and female rats were able to receive a dose of cocaine by pushing a lever. When they pushed the lever, a light was also activated.
This is to create a basic system of environmental triggers linked with drug use.
When observing the rats, Calipari found that female rats made stronger associations with the light when their hormone levels were higher, and were more likely to continue pushing the lever to receive cocaine.
As she explains in the report, the female rats were more responsive and willing to “pay” more in the presence of environmental cues to get cocaine.
“We found that the animals will press a lever just to get the light — that environmental stimuli,” Calipari said. “That has value to them.
“There’s epidemiological data that says women are more vulnerable, but it’s unclear what the factors are. We know they transition to addiction faster and have more problems with craving and relapse. Now, with research like this, we’re beginning to isolate environmental and physiological causes.”