Oral contraceptives and cognition: A systematic review

Effect of combined oral contraceptive use on verbal memory function in healthy women

PURPOSE

Female sex hormones as well as the synthetic hormones contained within combined oral contraceptives (COCs) may influence emotional and cognitive functioning including learning and memory; however, findings are inconsistent. We here present the largest study to date investigating the effect of COC use on verbal memory in healthy women.

METHODS

COC use and verbal memory scores were available from the CIMBI database for 205 healthy women in the reproductive age. We assessed if verbal memory and affective bias differed between COC users and non-users. In a subgroup of natural cycling women in the follicular phase, we assessed if verbal memory was associated with plasma estradiol levels.

RESULTS

We found no statistically significant group differences in either overall memory performance (p = 0.16) or affective memory bias (p = 0.18) between COC users and non-users, although there was a trend suggesting COC users may exhibit slightly better recall for short-term (p = 0.09) and long-term task (p = 0.08) conditions. Similarly, COC users tended to have slightly better overall memory compared with women in the follicular phase (p = 0.05). Follicular phase plasma estradiol levels were not associated with verbal memory.

CONCLUSIONS

We found no support for COC use to negatively impact verbal memory, if anything COC users tended to perform better than natural cycling women in follicular phase; however, this could be influenced by a healthy user bias. In conclusion, these findings highlight that women who tolerate COCs well should not be concerned about potential adverse effects on memory.

Perceived cognitive functioning difficulties in individuals living with endometriosis

Difficulties in cognitive functioning (e.g., memory, attention) are common in chronic conditions characterized by physical pain, fatigue and depression. Yet investigations in endometriosis are lacking. We aimed to assess: (1) perceived cognitive functioning, (2) the association of cognitive functioning with fatigue, pain and depressive symptoms, and (3) whether endometriosis treatments moderated these relationships. Participants (n = 1239) with diagnosed endometriosis completed an online survey assessing perceived cognitive functioning [Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog)], pain, fatigue and depression. FACT-Cog scores indicated cognitive impairments in 80% of participants. Hierarchical regression analyses demonstrated that greater pain, fatigue, and depressive symptoms were associated with poorer perceived cognitive functioning. Moderation analyses indicated that taking hormonal treatments or pain medications diminished the adverse effects of depression, but exacerbated the adverse effects of pain, on cognitive functioning. The extensive perceived cognitive difficulties evident in this sample suggests that supportive interventions to enhance cognitive functioning may be warranted.

Testing the congruency hypothesis using meta-analysis: Are changes in oral contraceptive use correlated with partnered women's sexual satisfaction?

Based on claims that changes in women's hormone levels influence their mating psychology, the Congruency Hypothesis proposes that women in relationships who change their hormonal contraceptive use after meeting their partner will report lower sexual satisfaction with their partner than women who do not change their oral contraceptive use. However, findings from studies testing this hypothesis have reported mixed results. Consequently, we conducted a meta-analysis of published studies on this topic. For the thirteen effects sizes from studies using between-subjects designs, the pooled correlation between congruency and sexual satisfaction was not statistically significant (r = 0.04, p = .091) and a Robust Bayesian meta-analysis found that the null hypothesis was moderately favoured over the Congruency Hypothesis (BF10 = 0.123, i.e., BF01 = 8.13, r = 0.003). For the four effect sizes from studies using within-subjects designs, the pooled correlation between congruency and sexual satisfaction was statistically significant (r = 0.18, p = .001) and a Robust Bayesian meta-analysis found weak evidence in favour of the Congruency Hypothesis (BF10 = 1.55, r = 0.09). Although the effect of congruency on sexual satisfaction may be statistically significant in some analyses, across all analyses, results indicated that the magnitude of the congruency effect was small. Thus, we suggest that it is unlikely that changes in oral contraceptive use have a substantial (i.e., large) effect on women's sexual satisfaction on average. Still, some women might experience congruency effects and the overall evidence remains uncertain. More work, ideally in the form of randomized controlled trials, is needed to find a definite answer for research questions relying on the Congruency Hypothesis.

Cognitive traits shape the brain activity associated with mental rotation

Mental rotation is a spatial cognitive ability influenced by several factors, including cognitive traits. However, the relationship between mental rotation performance, cognitive traits, and brain activity is still uncertain. To fill this gap, we recorded functional magnetic resonance imaging data while 55 neurotypical participants performed mental rotation with images of geometric objects, human bodies, and real objects. Cognitive traits were evaluated through the Object-Spatial Imagery Questionnaire (visual cognitive style), a perspective-taking task, and the Cognitive Flexibility Scale. Analysis of accuracy and reaction time revealed that (i) mental rotation in spatial-visualizers was more accurate and faster than in object-visualizers, and (ii) visual cognitive style and perspective-taking positively correlated with mental rotation. Brain activity data indicated that (i) individuals with better mental rotation performance had smaller brain activation, particularly in sensorimotor regions, (ii) for the spatial-visual scale and perspective-taking, high scorers had smaller brain activity than low performers, (iii) for the object-visual scale, high scorers had greater brain activity than low scorers. Supporting a neural efficiency hypothesis, the present study highlights the influence of cognitive traits on mental rotation performance and brain efficiency, with spatial-visualizers showing more efficient neural processing. These findings contribute to our understanding of how cognitive styles shape spatial cognition.

Own-gender bias in facial feature recognition yields sex differences in holistic face processing

INTRODUCTION

Female observers in their luteal cycle phase exhibit a bias towards a detail-oriented rather than global visuospatial processing style that is well-documented across cognitive domains such as pattern recognition, navigation, and object location memory. Holistic face processing involves an integration of global patterns and local parts into a cohesive percept and might thus be susceptible to the influence of sex and cycle-related processing styles. This study aims to investigate potential sex differences in the part-whole effect as a measure a of holistic face processing and explores possible relationships with sex hormone levels.

METHODS

147 participants (74 male, 51 luteal, 22 non-luteal) performed a part-whole face recognition task while being controlled for cycle phase and sex hormone status. Eye tracking was used for fixation control and recording of fixation patterns.

RESULTS

We found significant sex differences in the part-whole effect between male and luteal phase female participants. In particular, this sex difference was based on luteal phase participants exhibiting higher face part recognition accuracy than male participants. This advantage was exclusively observed for stimulus faces of women. Exploratory analyses further suggest a similar advantage of luteal compared to non-luteal participants, but no significant difference between non-luteal and male participants. Furthermore, testosterone emerged as a possible mediator for the observed sex differences.

CONCLUSION

Our results suggest a possible modulation of face encoding and/or recognition by sex and hormone status. Moreover, the established own-gender bias in face recognition, that is, female advantage in recognition of faces of the same gender might be based on more accurate representations of face-parts.

Supplementary motor area is deactivated during mental rotation tasks with biomechanical constraints in fMRI

Introduction

Mental rotation (MR) tasks of body parts involve anatomically interconnected brain systems. The systems are implicated in sensorimotor information integration and activate cortical motor-related areas, corresponding to the execution of similar motor tasks. In this study, we aimed to investigate the effect of varying the angle in the hand MR task on cerebral activation of the motor-related areas.

Methods

Twenty healthy right-handed participants were recruited. We investigated cerebral activation while each participant decided whether a hand-palm image, rotated by 0°, 90°, 180°, and 270°, was a right or left hand.

Results and discussion

A significant negative correlation between the angle and brain activity was observed in the right and left supplementary motor area (SMA) and right posterior anterior cingulate gyrus. The SMA was inactivated with 180°- or 270°-rotated images in the regions of interest analysis. 180°- and 270°-rotated palms would be biomechanically difficult to position; thus, SMA deactivation may be closely associated with biomechanical constraints. This study provided novel findings regarding the neurophysiological mechanisms of motor imagery and may be useful in developing treatment plans using MR tasks during patient rehabilitation.

Beyond Birth Control: The Neuroscience of Hormonal Contraceptives

Hormonal contraceptives (HCs) are one of the most highly prescribed classes of drugs in the world used for both contraceptive and noncontraceptive purposes. Despite their prevalent use, the impact of HCs on the brain remains inadequately explored. This review synthesizes recent findings on the neuroscience of HCs, with a focus on human structural neuroimaging as well as translational, nonhuman animal studies investigating the cellular, molecular, and behavioral effects of HCs. Additionally, we consider data linking HCs to mood disorders and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and stress response as a potential mediator. The review also addresses the unique sensitivity of the adolescent brain to HCs, noting significant changes in brain structure and function when HCs are used during this developmental period. Finally, we discuss potential effects of HCs in combination with smoking-derived nicotine on outcomes of ischemic brain damage. Methodological challenges, such as the variability in HC formulations and user-specific factors, are acknowledged, emphasizing the need for precise and individualized research approaches. Overall, this review underscores the necessity for continued interdisciplinary research to elucidate the neurobiological mechanisms of HCs, aiming to optimize their use and improve women's health.

Degraded Visibility Body-Specifically Affects Mental Rotation

The way we perceive our own body is shaped by our perception. Changes in sensory input, such as visual degradation, can lead to visual-to-motor shifts in the reference frame used to mentally represent the body. While this effect has been demonstrated in mental representation of hands, it is still unknown whether it also affects mental representation of other body parts. To fill this gap, we asked 35 neurotypical participants to perform mental rotation (laterality judgement) of hand, foot, and full-body images, while the images' visibility (figure/background contrast) was manipulated. Visibility deteriorations increased the steepness of the response time (RT) slopes for mental rotation of hand images shown from a less common view (palm) and of foot images from a more common view (dorsum), but not of full-body images from either the common or uncommon views. Suggesting that steeper and flatter RT slopes evoke the activation of a motor- or vision-based cognitive strategy for mental rotation, respectively, we propose that visual deterioration induces body-specific visual-to-motor shifts in mental processing. These findings show that the reliance on visual or motor aspects to mentally represent the body can be modulated by a reduction in sensory input, which changes the employed cognitive strategy.

Hormonal contraceptives and behavior: Updating the potent state of the nascent science

Hundreds of millions of people worldwide use hormonal contraceptives (HCs), which have been an essential part of women's reproductive health care for decades. Throughout that time, however, research on the neural and behavioral consequences of HCs was minimal and plagued by poor methodology. HC effects - and users - were assumed to be homogenous. Fortunately, there has been a recent upswell in the number and quality of investigations, affording tentative conclusions about the roles of HCs in spatial cognition and mental health, particularly depression. Thus, this paper leverages findings from the past few years to highlight the heterogeneous aspects of use that seem to matter for behavior - ranging from variation in hormonal contraceptive formulations and routes of administration to individual differences among users linked to age and reproductive health history. This paper closes with five tips for future research that will help capture and clarify heterogeneity in potential relations between HCs and behavior, namely data collection, regional access, lifespan factors, gender, and collaboration. HCs are sociopolitically provocative and research on their potential behavioral neuroendocrine impacts is becoming increasingly popular. It is, therefore, imperative for scientists to conduct replicable and robust empirical investigations, and to communicate findings with the nuance that the heterogeneity among users and effects requires.

Repeated exposure to physiologically effective doses of contraceptive hormones ethinyl estradiol or levonorgestrel do not alter the reinforcing effects of a brief visual stimulus in ovary-intact rats

Estradiol and progesterone potentiate and attenuate reward processes, respectively. Despite these well-characterized effects, there is minimal research on the effects of synthetic estrogens (e.g., ethinyl estradiol, or EE) and progestins (e.g., levonorgestrel, or LEVO) contained in clinically-utilized hormonal contraceptives. The present study characterized the separate effects of repeated exposure to EE or LEVO on responding maintained by a reinforcing visual stimulus. Forty ovary-intact female Sprague-Dawley rats received either sesame oil vehicle (n = 16), 0.18 μg/day EE (n = 16), or 0.6 μg/day LEVO (n = 8) subcutaneous injections 30-min before daily one-hour sessions. Rats' responding was maintained by a 30-sec visual stimulus on a Variable Ratio-3 schedule of reinforcement. The day after rats' last session, we determined rats estrous cycle phase via vaginal cytology before sacrifice and subsequently weighing each rat's uterus to further verify the contraceptive hormone manipulation. The visual stimulus functioned as a reinforcer, but neither EE nor LEVO enhanced visual stimulus maintained responding. Estrous cytology was consistent with normal cycling in vehicle rats and halting of normal cycling in EE and LEVO rats. EE increased uterine weights consistent with typical uterotrophic effects observed with estrogens, further confirming the physiological impacts of our EE and LEVO doses. In conclusion, a physiologically effective dose of neither EE nor LEVO did not alter the reinforcing efficacy of a visual stimulus reinforcer. Future research should characterize the effects of hormonal contraceptives on responding maintained by other reinforcer types to determine the generality of the present findings.

On the relation between oral contraceptive use and self-control

In two studies we examined the relation between oral contraceptive (OC) use and self-reported levels of self-control in undergraduate women using OCs (Study 1: OC group N = 399, Study 2: OC group N = 288) and naturally cycling women not using any form of hormonal contraceptives (Study 1: Non-OC group N = 964, Study 2: Non-OC group N = 997). We assessed the self-overriding aspect of self-control using the Brief Self-Control Scale (BSCS) and strategies for self-regulation using the Regulatory Mode Scale (RMS), which separately measures the tendency to assess one's progress towards a goal (assessment), and the tendency to engage in activities that move one towards an end goal (locomotion). In Study 1, we found no significant differences between OC and non-OC groups in their levels of self-overriding or self-regulatory assessment. However, we found that those in the OC group reported significantly greater levels of self-regulatory locomotion compared to those in the non-OC group, even after controlling for depression symptoms and the semester of data collection. The findings from Study 2 replicated the findings from Study 1 in a different sample of participants, with the exception that OC use was also related to higher levels of assessment in Study 2. These results indicate that OC use is related to increases in self-regulatory actions in service of goal pursuit and perhaps the tendency to evaluate progress towards goals.

Sex and gender correlates of sexually polymorphic cognition

BACKGROUND

Sexually polymorphic cognition (SPC) results from the interaction between biological (birth-assigned sex (BAS), sex hormones) and socio-cultural (gender identity, gender roles, sexual orientation) factors. The literature remains quite mixed regarding the magnitude of the effects of these variables. This project used a battery of classic cognitive tests designed to assess the influence of sex hormones on cognitive performance. At the same time, we aimed to assess the inter-related and respective effects that BAS, sex hormones, and gender-related factors have on SPC.

METHODS

We recruited 222 adults who completed eight cognitive tasks that assessed a variety of cognitive domains during a 150-min session. Subgroups were separated based on gender identity and sexual orientation and recruited as follows: cisgender heterosexual men (n = 46), cisgender non-heterosexual men (n = 36), cisgender heterosexual women (n = 36), cisgender non-heterosexual women (n = 38), gender diverse (n = 66). Saliva samples were collected before, during, and after the test to assess testosterone, estradiol, progesterone, cortisol, and dehydroepiandrosterone. Psychosocial variables were derived from self-report questionnaires.

RESULTS

Cognitive performance reflects sex and gender differences that are partially consistent with the literature. Interestingly, biological factors seem to better explain differences in male-typed cognitive tasks (i.e., spatial), while psychosocial factors seem to better explain differences in female-typed cognitive tasks (i.e., verbal).

CONCLUSION

Our results establish a better comprehension of SPC over and above the effects of BAS as a binary variable. We highlight the importance of treating sex as a biological factor and gender as a socio-cultural factor together since they collectively influence SPC.

The role of sex hormones, oral contraceptive use, and its parameters on visuospatial abilities, verbal fluency, and verbal memory

Sex hormones can cross the blood-brain barrier and access brain regions underlying higher-order cognition. Containing synthetic sex hormones, oral contraceptives (OC) have been found to modulate visuospatial and verbal abilities, though inconsistencies have been found in the literature. Among possible explanations, certain OC use parameters (progestin androgenicity, synthetic hormone levels, duration of use) have not received consistent consideration. Thus, the objectives were to (1) examine group differences between men, combined OC users, and naturally cycling women (NC women; not using OC) in visuospatial abilities, verbal fluency, and verbal memory and (2) investigate the contribution of endogenous and exogenous sex hormones on these effects. We also aimed to (3) identify OC use parameters relevant to cognitive outcomes. In total, 70 combined OC users, 53 early follicular (EF) women, 43 pre-ovulatory (PO) women, and 47 men underwent cognitive tests. Performance was compared based on hormonal milieus (OC, EF, PO, men) and OC users' contraceptive androgenicity (anti, low, high). Correlations between performance, hormone levels and OC use duration were also conducted. OC use dampened the sex difference that typically favors men in 3D visuospatial abilities, whereas its duration of use positively predicted verbal fluency. Androgenicity and hormone levels did not predict performance in any task. These results highlight the importance of considering OC use duration. Results also did not support a role for androgenicity in cognition. Importantly, combined OC use (including prolonged use) does not impair visuospatial, verbal, and memory functions in a healthy young sample.

Examining the relation between oral contraceptive use and attentional engagement in everyday life

Oral contraceptives (OCs) used by women worldwide include artificial estradiol and progesterone, which can attach to receptors in the brain and potentially influence cognition. In the present studies, we examined the relation between OC use and self-reported everyday attention. We collected trait-level measures of mind wandering, attention-related errors, and attention lapses in undergraduate women using OCs (Study 1: OC group N = 471, Study 2: OC group N = 246) and naturally cycling women not using any form of hormonal contraceptives (Study 1: Non-OC group N = 1,330, Study 2: Non-OC group N = 929). In Study 1, we found that women using OCs reported significantly less spontaneous and deliberate mind wandering than naturally cycling women and no differences between groups on attention-related errors and attention lapses. In Study 2, our findings indicated no significant differences between groups on any of our attention measures. Regression analyses controlling for depression symptoms and semester of data collection found that OC use did predict unique additional variance on some attention measures, but these effects were small and unreliable across the two studies. Taken together, our data suggests there is little evidence that OC use is related to differences in attentional engagement in everyday life.