Studies Shrinking brain through contraceptive pill

Birth control pills: Hormonal contraceptives cause the brain to shrink
Despite the known side effects, birth control pills are still relatively popular among women in Germany as a contraceptive. However, a recent study by scientists at the University of California and Harvard Medical Schoool shows that taking the pill also shrinks individual areas of the brain.

Neuroscientists led by Nicole Petersen of the University of California, Los Angeles, have found that hormonal contraception using birth control pills shrinks the lateral orbitofrontal cortex and the posterior cingulate cortex. These regions play a vital role in responding to rewards and evaluating internal states of emotions or in-depth stimuli. Thus, the proven changes in the brain structures may possibly be the cause of known side effects of birth control pills such as anxiety attacks or depressive episodes.

Taking birth control pills leads to changes in the brain. (Image: nimon_t / fotolia.com)

Changed volume of individual brain regions
In 90 women (44 users of the pill, 46 with a natural cycle), the scientists examined the thickness or volume of various brain regions in order to detect possible impairments due to hormonal contraception. Using MRI images, they were able to show that taking the pill leads to a significantly lower thickness in the lateral orbitofrontal cortex and the posterior cingulate. Significant changes were also noted in other brain regions. It can be assumed that at least some of the effects on synthetic hormones in birth control pills can be attributed, the scientists report.

Duration of impairment unclear
During the approximately one-week break, the women take when taking the pill every month, the brain changes have partially declined, write Nicole Petersen and colleagues on. This suggests that the impairments are theoretically reversible, but further studies would have to clarify to what extent a normalization of the brain structures after discontinuation of the pill is achievable or whether the changes for weeks, months, years or persist. However, in view of the results, it can be assumed that, at least temporarily, emotion regulation is less effective for users of the pill. However, further investigations are needed to substantiate this assumption.

Further studies required
Furthermore, the current study results contrast with a study from 2010 in which an increase in the gray matter due to birth control pills in various brain regions was found. In the opinion of the researchers this may be due to the different hormonal agents of the different preparations and to the different examination methods. Here, too, further differentiated study of the various hormonal agents is required. (Fp)