A student-directed ASU study conducted on the birth-control shot Depo Provera suggests that the shot may be linked to long-term memory loss.
The two-part study, led by psychology graduate student Blair Braden and psychology professor Heather Bimonte-Nelson, demonstrated the link between medroxyprogesterone acetate and memory impairment in rodents. Part one of the study was published in January 2010, and part two was published May 2011.
MPA is the only hormone active in Depo Provera and is widely used in hormone therapy for post-menopausal women, Bimonte-Nelson said.
“We think this study is so important because what this is really doing is modeling what we are going to be seeing in upcoming years in women,” Bimonte-Nelson said.
Depo Provera is administered once every 12 weeks as a contraceptive and is considered 99 percent effective in preventing pregnancy.
The researchers began by administering the hormone to aged rats, resulting in increased cognitive damage in a “compromised” brain.
“That was very relevant because what that told us was that commonly used progestin had negative effects on cognition and it actually made aged rats worse,” Bimonte-Nelson said.
Braden said she found these results alarming, as she knew several women using Depo Provera.
“That led me to be pretty concerned, especially knowing other people that are taking this birth control,” Braden said.
The experiment was then expanded to include younger rats to see if the hormone could affect brains of healthier rodents.
The study showed young rats suffered memory loss, even after MPA had been out of their systems for four months, Bimonte-Nelson said.
“What we showed was that MPA, at any time point in your life, had a negative impact when you were old,” Bimonte-Nelson said.
Braden said she was shocked with the result of the second study.
“To see even in a much healthier, younger brain that it could still have these detrimental effects is really surprising,” Braden said.
Bimonte-Nelson said the researchers are now one-third of the way through a study applying their findings to women.
She said the next step is to understand the reactions in the brain that cause the hormone to impair memory.
Braden said the studies show women should research their birth control options before committing to a treatment like Depo Provera.
“The choice to use hormones for birth control or hormone therapy is a choice every woman has to make so the more informed you can be about your options, the better,” Braden said.
Reach the reporter at brennan.j.smith@asu.edu Click here to subscribe to the daily State Press newsletter.
