New research reveals why women get addicted to cocaine faster than men
SUMMARY: Hormonal fluctuations in women make them more prone than men to cocaine’s addictive properties, according to a recent study at the Icahn School of Medicine.
A team of researchers at the Icahn School of Medicine at Mount Sinai Hospital wanted to explore why women are more likely than men to become addicted to cocaine when they try the drug. Previous research has shown that although more men in total use and are addicted to cocaine, women who try the drug are more likely to continue its use, take the drug in larger quantities, and have a harder time quitting the drug than men do.
The surprising result of the study: Hormonal fluctuations in women may be the culprit behind the addictive behavior. The researchers found that estrogen impacts the dopamine reward pathway of the brain and that the effects of the drug are intensified during different times in a woman’s monthly menstrual cycle. This means that as woman’s estrogen level increases she experiences a greater “high” from cocaine.
What does this research mean?
The exciting implications of this research are three-fold:
- There are possible hormone-based interventions (such as using birth control pills) to treat cocaine addiction
- Better understanding of females is needed in addiction research, which has mostly been conducted with male subjects
- Estrogen may also have similar effects for women with other abused substances, not just cocaine
“Our study will change the way we think about addiction research to emphasize the need to further understand female subjects, as most research on addiction has been conducted in male subjects,” says researcher Erin Calipari, PhD. “Further study of the estrogen-reward pathway is important, as it is quite possible that estrogen may have similar effects on other forms of substance abuse.”
Dr. Capilari is a member of the Laboratory of Molecular Psychiatry at the Icahn School of Medicine.
How the research was conducted
Mice were used as subjects for the study because mice have similar sex-based differences to cocaine as humans. Both male mice and female mice at different points in the estrus cycle were used. The researchers affixed fiber-optic probes to specific areas of the brains of the mice and then measured the effects of the dopamine released with cocaine administration. The research looked at the length of time the dopamine remained in the synapses between brain cells.
The researchers discovered that estrogen impacted not only the amount of dopamine released in the brain in response to the cocaine, but also how long the dopamine stayed in the synapses. Estrogen levels bolstered both of these effects, which link to heightened pleasure from cocaine.
“Our findings underscore the unique insight into normal brain function and disease pathology that results from studying both sexes,” says Eric Nestler, MD, PhD, the study’s lead investigator and Nash Family Professor of Neuroscience and Director of The Friedman Brain Institute at the Icahn School of Medicine. “This approach is essential to enable the field to develop optimized treatments for drug addiction and other conditions for women as well as men.”
FROM THE HHN EDITORS:
This is exciting research which could offer new insights on treatment options for women struggling with cocaine and other addictions. We will be watching for other research that focuses on the particular biochemical issues of females with regards to addiction.