Nav: Home

Women's hormones play role in drug addiction, higher relapse rates

February 08, 2019

Women's hormonal cycles may not only make them more prone to drug addiction but also more affected by triggers that lead to relapse, a new Vanderbilt University study revealed. The findings are especially significant since there are virtually no addiction studies in women that account for these cycles.

Erin Calipari, an assistant professor of pharmacology in the Vanderbilt Center for Addiction Research, points out that women represent a particularly vulnerable population, with higher rates of addiction following exposure to drugs, but addiction studies have primarily focused on the mechanisms underlying these effects in men. Her study found that, when fertility-related hormone levels are high, females learn faster, make stronger associations to cues in their environment and are more prone to seek rewards.

"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."

The next step, she said, would be to figure out specifics of how hormonal shifts affect women's brains and, ultimately, develop medications that could help override those. But long before those future medications are available, treatment centers could use the information in this study to educate women about their stronger mental connections to places and objects. That may mean a higher chance of relapse just by, for example, visiting a place where they used drugs or holding the kind of spoon they used in the process.

Researchers historically have avoided using female animals in medical studies specifically so they don't have to account for influences from hormonal cycles. As a result, medication development has often focused on correcting dysfunctions in men, which may explain why women often don't respond to available medications or treatments in the same way as men do, Calipari said.

Her work was published recently in the Nature-affiliated journal Neuropsychopharmacology in a paper titled "Cues play a critical role in estrous cycle-dependent enhancement of cocaine reinforcement."

In this study, male and female rats were allowed to dose themselves with cocaine by pushing a lever, with a light set up to come on during dosing. That's similar to the environmental cues, such as drug paraphernalia, present when humans are taking drugs. When their circulating hormone levels were high, female rats made stronger associations with the light and were more likely to keep pushing the lever as much as it took to get any amount of cocaine.

Ultimately, females were willing to "pay" more in the presence of these cues to get cocaine. The results are transferable to humans through behavioral economic analysis, which uses a complicated mathematical equation with values for the most and least a subject will do to get a payoff. It's one of the few ways that comparisons can be made across species.

"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."

This new research builds on earlier work Calipari published at the Icahn School of Medicine at Mount Sinai that showed estrogen intensifies the brain's dopamine reward for cocaine use.
-end-


Vanderbilt University

Related Cocaine Articles:

Chronic cocaine use modifies gene expression
Chronic cocaine use changes gene expression in the hippocampus, according to research in mice recently published in JNeurosci.
Blocking dopamine weakens effects of cocaine
Blocking dopamine receptors in different regions of the amygdala reduces drug seeking and taking behavior with varying longevity, according to research in rats published in eNeuro.
Born to run: just not on cocaine
A study finds a surprising response to cocaine in a novel strain of mutant mice -- they failed to show hyperactivity seen in normal mice when given cocaine and didn't run around.
Cocaine adulterant may cause brain damage
People who regularly take cocaine cut with the animal anti-worming agent levamisole demonstrate impaired cognitive performance and a thinned prefrontal cortex.
Setting affects pleasure of heroin and cocaine
Drug users show substance-specific differences in the rewarding effects of heroin versus cocaine depending on where they use the drugs, according to a study published in JNeurosci.
One in 10 people have traces of cocaine or heroin on their fingerprints
Scientists have found that drugs are now so prevalent that 13 percent of those taking part in a test were found to have traces of class A drugs on their fingerprints -- despite never using them.
Alcohol makes rats more vulnerable to compulsive cocaine use
Rats given alcohol for 10 days prior to cocaine exhibited enhanced cocaine-addiction behavior, including continuing to seek cocaine despite receiving a brief electric shock when they did so, a new study reports.
Cocaine use during adolescence is even more harmful than during adulthood
Brazilian scientists found that addicts who began using cocaine before and after the age of 18 showed differences in sustained attention and working memory, among other brain functions.
Cocaine addiction leads to build-up of iron in brain
Cocaine addiction may affect how the body processes iron, leading to a build-up of the mineral in the brain, according to new research from the University of Cambridge.
Potential new treatment for cocaine addiction
A team of researchers led by Cardiff University has discovered a promising new drug treatment for cocaine addiction.
More Cocaine News and Cocaine Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.