Synthetic Estrogen in Birth Control Linked to Anxiety

Summary: Researchers suggest that the type of estrogen in hormonal birth control influences anxiety-like behaviors. Researchers found that synthetic estrogen in birth control led to increased anxiety behaviors in female rats compared to natural estrogen.

This study highlights the importance of considering estrogen type when evaluating the behavioral side effects of contraceptives. The findings could guide clinical decisions to manage anxiety-related side effects in women using birth control.

Key Facts:

  1. Synthetic estrogen in birth control is linked to increased anxiety behaviors in female rats.
  2. The study used a rat model to compare synthetic ethinyl estradiol and natural estradiol valerate.
  3. Spatial memory was similar across groups, but synthetic estrogen increased habitual turn strategies associated with anxiety.

Source: The Endocrine Society

The type of estrogen in hormonal birth control may influence anxiety-like behaviors, according to data presented by Abigail Hegwood, M.S., from the Prakapenka Lab at ENDO 2024, the Endocrine Society’s annual meeting in Boston, Mass.

“It is plausible that estrogen type is a key player in mood or cognitive related side effects of hormone-based contraceptive use,” said Alesia Prakapenka, Ph.D., an assistant professor in the Biomedical Sciences program at Midwestern University in Downers Grove, Ill.

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After four weeks, the rats were evaluated on a delayed spontaneous alternation task to examine spatial memory and elevated plus maze to analyze anxiety-like behavior. Credit: Neuroscience News

According to the CDC, 12.6% of women in the United States between the ages of 15 and 49 reported using oral contraceptives from 2015 to 2017. Prakapenka and colleagues acknowledged that behavioral side effects are one of the reasons why many women stop taking combination birth control.

The researchers sought to understand whether or not identifying an estrogen type matters when it comes to evaluating behaviors like anxiety and cognition.

In this rat model study, the researchers randomly assigned 36 young adult female rats (aged 3 to 4 months old) to synthetic ethinyl estradiol plus dienogest, natural estradiol valerate plus dienogest, or vehicle control treatment.

After four weeks, the rats were evaluated on a delayed spontaneous alternation task to examine spatial memory and elevated plus maze to analyze anxiety-like behavior.

Then, Prakapenka explained, serum was extracted and examined for estradiol, progesterone, androstenedione, and testosterone levels using liquid chromatography-mass spectrometry and corticosterone levels using radioimmunoassay.

“We found that female rats treated with the synthetic estrogen exhibited elevated anxiety-like behaviors compared to females that received a vehicle control or the natural estrogen,” Prakapenka said, adding that spatial memory was similar across the three treatment groups.

Of note, navigation on the spatial memory task differed. The synthetic estrogen increased habitual turn strategy use compared to the control and natural estrogen–a finding that is associated with anxiety-like behaviors.

“Altogether, our findings support the notion that estrogen type matters for behavioral outcomes associated with contraceptive use, identifying estrogen type as a potential clinical tool for management of behavioral side effects in females,” Hegwood said.

About this psychopharmacology and anxiety research news

Author: Abigail Hegwood
Source: The Endocrine Society
Contact: Abigail Hegwood – The Endocrine Society
Image: The image is credited to Neuroscience News

Original Research: The findings will be presented at ENDO 2024

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