Oral contraceptive pill use is associated with localized decreases in cortical thickness

Abstract

Oral contraceptive pills (OCs), which are used to prevent pregnancy by the majority of women in the United States, contain steroid hormones that may affect the brain’s structure and function. In this investigation, we tested the hypothesis that OC use is associated with differences in brain structure using a hypothesis-driven, surface-based approach. In 90 women, (44 OC users, 46 naturally-cycling women), we compared the cortical thickness of brain regions that participate in the salience network and the default mode network, as well as the volume of subcortical regions in these networks. We found that OC use was associated with significantly lower cortical thickness measurements in the lateral orbitofrontal cortex and the posterior cingulate cortex. These regions are believed to be important for responding to rewards and evaluating internal states/incoming stimuli, respectively. Further investigations are needed to determine if cortical thinning in these regions are associated with behavioral changes, and also to identify whether OC use is causally or only indirectly related to these changes in brain morphology.

Predicting ovulation from brain connectivity: Dynamic causal modelling of the menstrual cycle

“…The present results not only corroborate previous findings in causal networks' dynamics but also suggest a further aspect of the insula's function related to its role in responding to changes in the endogenous hormonal milieu. Indeed, previous studies have already related the insula's morphology and resting state connectivity to women's hormonal status in a lateralized pattern 56,57 . In our sample, the left insula had higher connectivity to the anterior DMN during menses, while the right insula was more strongly connected to the posterior DMN and ECN.…”

Neuroimaging the Menstrual Cycle and Premenstrual Dysphoric Disorder

“…In line with these longitudinal studies, a recent and relatively large cross-sectional study demonstrated thicker right lateral orbitofrontal cortex in the early follicular as compared to the luteal phase [38]. Finally, when association with hormonal levels have been investigated, a number of correlations has been found, although relatively sparsely and with variable results [31••, 35, 37, 38].…”

“…Hormonal replacement appears to increase cerebral blood flow at rest in several cortical regions, and the cholinergic and serotonergic systems seem to act as biological mediators of hormonal influences on the brain [34]. On the other hand, findings of exogenous hormone exposure in studies of women in childbearing ages suggest various sex hormone effects on brain function [2••] and structure [32,38,42,106]. Hence, inadequate evidence is served up to estimate favorable versus disadvantageous effects of the ecological monthly hormonal fluctuations versus artificial steady levels on the brain.…”

Synthetic Hormone Dose in Hormonal Contraceptives Predicts Individual Differences in Personality

“…It is possible that the observed HC-related differences in personality may be a direct consequence of neurological alterations brought about by the pill. Recently, Petersen, Touroutoglou, Andreano, and Cahill 16 linked oral contraceptive use with localized decreases in cortical thickness in the lateral orbitofrontal cortex and the posterior cingulate cortex. These brain regions are believed to be involved in emotion regulation and the evaluation of internal states, respectively, 16 and have been linked to between-subjects differences in personality.…”