Birth Control Pill May Shrink your Brain
The oral contraceptive pill, commonly referred to as
“the pill,” has some troubling possible side effects, including mood
swings, weight gain and nausea. A new study adds another potential concern to
the list: the pill may shrink your brain.
Researchers from the University of California, Los Angeles published
their findings in the journal Human
Brain Mapping, on April 2nd, 2015. The study shows that the pill
may be linked to thinning a woman’s brain structure, specifically the lateral
orbitofrontal cortex and the posterior cingulate cortex.
For the study, Nicole Petersen, study author from the
department of psychiatry and bio behavioral sciences at UCLA and her colleagues
recruited 90 women, with 44 women on combined birth control and 46 women who
did not use any type of hormonal birth control.
When comparing participants’ brain scans, the team of neuroscientists
found that two key brain regions, the lateral orbitofrontal cortex and the
posterior cigulate cortex, were thinner in women who were on the pill compared
with women in the other group. The lateral orbitofrontal cortex plays an
important role in emotion regulation and responding to rewards, while the
posterior cigulate cortex is involved with inward-directed thought, and shows
increased activity when we recall personal memories and plan for the future. Changes
in the lateral orbitofrontal cortex could be responsible for the increased
anxiety and depressive symptoms that some women experience when they start
taking the Pill.
“Some women experience negative emotional side effects
from taking oral contraceptive pills, although the scientific findings
investigating that have been mixed,” Dr. Petersen said. “So it’s
possible that this change in the lateral orbitofrontal cortex may be related to
the emotional changes that some women experience when using birth control
However, this does not suggest changes in cortex thickness
are reflected in any actual changes in the behavior of women who take the pill.
Moreover, the study does not prove taking birth control causes the thinning of
The researchers affirm it is unknown whether the cortex
would become thicker again if the women on birth control stopped taking the
pill or whether it would remain the same. “Maybe you go off the pill and
it persists for a week, and, by week two it is back to normal.”
The team does stress the role of estrogen in the brain.
“There is a ton of evidence showing that estrogen is a really important
molecule for brain growth,” Dr. Petersen said. The researchers hope to
conduct a clinical trial to see if there is a casual relationship between the
pill and brain structure, and whether any behavior changes related to the two
cortex regions can be seen.
Furthermore, all risks associated with the pill increase if
a woman smokes, has thrombosis, is overweight, diabetic, has high blood
pressure, or high cholesterol levels.