The effects of diazepam on fear extinction in nulliparous and primiparous female rats.

Benzodiazepines undermine the success of exposure therapy in humans with anxiety disorders, and impair the long-term memory of fear extinction (the laboratory basis of exposure therapy) in rodents. However, most rodent studies on fear extinction and benzodiazepines have been conducted in male rodents. In female rodents, the estrous cycle influences the consolidation of fear extinction memories and sensitivity to benzodiazepines. In addition, pregnancy leads to long-term changes in the neurobiological, hormonal, and behavioural features of fear extinction, as well as the responsivity to benzodiazepines. Therefore, the present experiments examined the impact of benzodiazepines on fear extinction in female rats with and without reproductive experience. Age-matched nulliparous (no reproductive experience) and primiparous (one prior reproductive experience; tested one-month post-weaning) rats received fear conditioning to a discrete cue. The next day, rats were administered the benzodiazepine diazepam (2 mg/kg, s.c), or vehicle, prior to or immediately after extinction training. Rats were then tested the next day, drug free, for extinction retention. Similar to previous findings in males, diazepam impaired extinction retention in both nulliparous and primiparous rats when administered either pre- or post-extinction training. These findings may have potential clinical implications as they suggest that benzodiazepine use in conjunction with exposure therapy may undermine long-term treatment success in women with and without reproductive experience, although this remains to be tested in human populations. Moreover, these findings are theoretically important when considered in light of previous studies showing dissociable mechanisms of fear extinction in females pre- versus post-pregnancy.

The impact of hormonal contraceptives on anxiety treatments: From preclinical models to clinical settings.

Exposure therapy is a central component of the first-line treatment for anxiety disorders, a common mental health condition that is twice as prevalent in women relative to men. A key underlying mechanism of exposure therapy is fear extinction, which is an active learning process supported by a neural circuitry that is highly regulated by ovarian hormones. This review synthesises research examining the impact of hormonal contraceptives on laboratory fear extinction tasks in female rats and women, and on exposure therapy in women with anxiety disorders. The evidence indicates that hormonal contraceptives have a detrimental impact on fear extinction and exposure therapy that is consistent across species, and from laboratory to clinical settings. Candidate pathways by which hormonal contraceptives impede fear extinction and exposure therapy include suppression of endogenous ovarian hormones and glucocorticoids, and downregulation of signalling pathways that support extinction learning. Key areas of focus for future research are discussed.

Dissociable role of the basolateral complex of the amygdala in the acquisition and extinction of conditioned fear following reproductive experience in female rats.

In female rats and humans, reproductive experience (i.e., pregnancy) alters the behavioral, hormonal and molecular substrates of fear extinction. Here, we assessed whether the role of a central neural substrate of fear extinction, the basolateral amygdala (BLA), also changes following reproductive experience. Nulliparous (virgin) and primiparous (one prior pregnancy) female rats received infusions of the GABAA agonist, muscimol, to temporarily inactivate the BLA prior to fear conditioning or extinction training. In follow up experiments, the BLA was also inactivated immediately after extinction training. BLA inactivation impaired the acquisition and expression of conditioned fear in both nulliparous and primiparous rats. In nulliparous rats, BLA inactivation prior to or immediately after extinction training impaired extinction retention. In contrast, in primiparous rats, BLA inactivation prior to or immediately after extinction training did not impair extinction retention, despite suppressing freezing during extinction training. These results suggest that, consistent with past findings in males, the BLA is a central component of the neural circuitry of fear acquisition and its extinction in virgin female rats. However, after pregnancy, female rats no longer depend on the BLA to extinguish fear, despite requiring the BLA to acquire conditioned fear. Given that fear extinction forms the basis of exposure therapy for anxiety disorders in humans, the present findings may have clinical implications. To improve the efficacy of exposure therapy for anxiety disorders, we may need to target different mechanisms in females dependent on their reproductive history.

What Pre-clinical Rat Models Can Tell Us About Anxiety Across the Menstrual Cycle in Healthy and Clinically Anxious Humans.

PURPOSE OF REVIEW: Anxiety symptoms increase during the peri-menstrual phase of the menstrual cycle in people with anxiety disorders. Whether this reflects a heightened variant of normal menstrual-related changes in psychological states experienced by healthy (i.e. non-anxious) people is unknown. Moreover, menstrual-related change in anxiety symptoms is a poorly understood phenomenon, highlighting a need for pre-clinical models to aid mechanistic discovery. Here, we review recent evidence for menstrual effects on anxiety-like features in healthy humans as a counterpart to recent reviews that have focused on clinically anxious populations. We appraise the utility of rodent models to identify mechanisms of menstrual effects on anxiety and offer suggestions to harmonise methodological practices across species to advance knowledge in this field. RECENT FINDINGS: Consistent with reports in clinical populations, some evidence indicates anxiety symptoms increase during the peri-menstrual period in healthy people, although null results have been reported, and these effects are heterogeneous across studies and individuals. Studies in rats show robust increases in anxiety during analogous phases of the oestrous cycle. Studies in female rats are useful to identify the evolutionarily conserved biological mechanisms of menstrual-related changes in anxiety. Future experimental approaches in rats should model the heterogeneity observed in human studies to increase alignment across species and advance understanding of the individual factors that increase the propensity to experience menstrual-related changes in anxiety.

Symptom fluctuation over the menstrual cycle in anxiety disorders, PTSD, and OCD: a systematic review.

Anxiety disorders are more prevalent and severe in women than men. Extant research suggests that the menstrual cycle modulates the severity and expression of anxiety symptoms across a range of disorders. The aims of this systematic review were to synthesise the existing literature investigating menstrual phase-related fluctuations in symptoms of anxiety disorders, and related conditions PTSD and OCD, in menstruating women, and to evaluate the methodologies used. PsycINFO and PubMed were searched through to April 2021 for studies that measured and compared symptoms of a diagnosed anxiety disorder, PTSD, or OCD, between at least two menstrual phases. Fourteen studies meeting inclusion criteria were identified. The review revealed evidence for exacerbation of a broad range of symptoms in panic disorder, PTSD, social anxiety disorder, and generalised anxiety disorder, around the weeks prior to and post menses onset, coincident with elevated but declining ovarian hormones, and low hormone levels, respectively. Effects were heterogenous between individuals and different symptom types. Key methodological weaknesses included sub-optimal and inconsistent means of defining and identifying menstrual phases, low sample representativeness, and small sample sizes. Menstrual fluctuations in anxiety symptoms appear to be a feature of anxiety disorders, PTSD, and OCD, but likely only occur in a subset of women. Future research in this field could better manage and account for such heterogeneity by using group-based trajectory modelling in larger sample sizes and using pre-screening to recruit women with known histories of menstrual fluctuation in anxiety symptoms.

The relationship between repetitive negative thinking, sleep disturbance, and subjective fatigue in women with Generalized Anxiety Disorder.

OBJECTIVES: Fatigue is a prominent symptom of Generalized Anxiety Disorder (GAD). However, the pathways contributing to elevated fatigue in GAD are poorly understood. Sleep disturbance, also prominent in GAD, only partially explains elevated fatigue in GAD. Repetitive negative thinking (RNT) is a cognitive feature of both GAD and sleep disturbance, and RNT has recently also been associated with elevated fatigue. Therefore, this study assessed whether elevated fatigue in GAD is accounted for by a combination of sleep quality and RNT. DESIGN: Between-group, correlational design in 64 primarily university-educated women with and without a GAD diagnosis. METHODS: Women completed self-report questionnaires assessing RNT experienced in the past few days, previous night's sleep quality, and current physical and mental fatigue. Hierarchical linear regressions were conducted to assess whether the relationship between GAD status and fatigue is accounted for by RNT and sleep quality. RESULTS: Women with GAD reported lower sleep quality, and higher RNT and physical and mental fatigue, compared to women without GAD. Sleep quality partly accounted for group differences in both types of fatigue (ß's > -0.4), whereas RNT fully accounted for group differences in both types of fatigue (ß's > 0.29). The relationship between RNT and both types of fatigue was fully accounted for by sleep quality (ß's > -0.39). CONCLUSIONS: These findings indicate that heightened RNT amongst women with GAD may be associated with elevated physical and mental fatigue via its detrimental effects on sleep quality. Interventions that reduce RNT may help to alleviate fatigue symptoms in women with GAD. PRACTITIONER POINTS: Women with Generalized Anxiety Disorder (GAD) have elevated fatigue and repetitive negative thinking (RNT), and poorer self-reported sleep quality, relative to women without GAD. Whereas sleep quality only partially accounts for elevated fatigue in GAD, RNT fully accounts for elevated fatigue, and the relationship between RNT and fatigue is fully accounted for by sleep quality. These findings provide novel evidence that women with GAD may have elevated fatigue because of the detrimental effects of RNT on sleep. These findings suggest that targeting RNT in treatment for GAD may help to reduce fatigue in GAD, by improving sleep quality.

It's all about who you know: Memory retention of a rat's cagemates during infancy negatively predicts adulthood hippocampal FGF2.

Recent research has demonstrated that individual differences in infant fear memory positively predict adulthood anxiety-like behavior and conditioned fear expression. However, the physiological mechanisms underlying this relationship and the effect of environmental (e.g., social) influences on the stability of this relationship have not been explored. In the present study, we examined whether individual differences in infant fear memory predict levels of endogenous fibroblast growth factor-2 (FGF2; a biomarker of fear/anxiety) in adulthood, and whether the mean memory retention of a rat's cagemates predicts conditioned fear expression and FGF2 in adulthood. We conditioned infant rats to associate a white noise with shock, and tested their memory of the association 1 week later. They were then weaned and randomly assigned to cage/cagemates. In adulthood, rats received weak context conditioning (i.e., a single shock) and were tested for fear of the context the following day. Rats were then euthanized and their brains extracted to measure levels of hippocampal FGF2 protein. Across 2 experiments, an individual rat's fear memory during infancy positively predicted their own fear expression in adulthood, but the mean memory retention of their cagemates did not predict fear expression. In contrast, the mean memory retention of a rat's cagemates during infancy negatively predicted hippocampal FGF2 protein in adulthood, but an individual rat's memory retention did not predict their own levels of FGF2. These data support the idea that variations in the fearfulness of a rat's cagemates predict individual differences on physiological measures in adulthood.

Cannabinoid polymorphisms interact with plasma endocannabinoid levels to predict fear extinction learning.

BACKGROUND: The endocannabinoid system is gaining increasing attention as a favorable target for improving posttraumatic stress disorder (PTSD) treatments. Exposure therapy is the gold-standard treatment for PTSD, and fear extinction learning is a key concept underlying successful exposure. METHODS: This study examined the role of genetic endocannabinoid polymorphisms in a fear extinction paradigm with PTSD compared to healthy participants (N = 220). Participants provided saliva for genotyping, completed a fear conditioning and extinction task, with blood samples taken before and after the task (n = 57). Skin conductance was the outcome and was analyzed using mixed models. RESULTS: Results for cannabinoid receptor type 1 polymorphisms suggested that minor alleles of rs2180619 and rs1049353 were associated with poorer extinction learning in PTSD participants. The minor allele of the fatty acid amide hydrolase (FAAH) polymorphism rs324420 was associated with worse extinction in PTSD participants. Subanalysis of healthy participants (n = 57) showed the FAAH rs324420 genotype effect was dependent on plasma arachidonoyl ethanolamide (AEA) level, but not oleoylethanolamide or 2-arachidonoyl glycerol. Specifically, higher but not lower AEA levels in conjunction with the minor allele of FAAH rs324420 were associated with better extinction learning. CONCLUSIONS: These findings provide translational evidence that cannabinoid receptor 1 and AEA are involved in extinction learning in humans. FAAH rs324420's effect on fear extinction is moderated by AEA plasma level in healthy controls. These findings imply that FAAH inhibitors may be effective for targeting anxiety in PTSD, but this effect needs to be explored further in clinical populations.

Hormonal, reproductive, and behavioural predictors of fear extinction recall in female rats.

The prevalence, severity and chronicity of anxiety disorders is significantly higher in women compared to men. Exposure therapy, the gold-standard treatment for anxiety disorders, can be modelled in the laboratory through Pavlovian fear extinction. Understanding the factors that influence fear extinction in females may aid in optimising the treatment of anxiety disorders in this population. The aim of the current study was therefore to explore the hormonal, reproductive and behavioural predictors of fear extinction recall in female rats by analysing data from nine published experiments that examined fear extinction in female rats. A hierarchical multiple regression analysis revealed that estrous cycle effects on extinction recall may be modulated by reproductive status. While the estrous phase in which nulliparous (virgin) rats undergo extinction training was predictive of extinction recall, no relationship between estrous phase and extinction recall was found among primiparous (one prior reproductive experience) rats. Moreover, estrous cycle predicted the relationship between early extinction and extinction recall in nulliparous rats, but not primiparous rats. Although reproductive status did not predict extinction recall, primiparous rats exhibited poor extinction recall relative to nulliparous rats extinguished during proestrus, and better extinction recall than nulliparous rats extinguished during metestrus. A faster rate of extinction, and lower fear responses at the end of extinction training were predictive of lower levels of CS-elicited fear during extinction recall in both nulliparous and primiparous female rats, while the length of extinction training was not predictive of extinction recall. The potential theoretical and clinical implications of these findings are discussed.

Physical and mental fatigue across the menstrual cycle in women with and without generalised anxiety disorder.

Subjective, disabling fatigue is a common complaint and a key feature of numerous medical conditions, and is a transdiagnostic feature of psychiatric disorders. Despite physical and mental fatigue being associated with functional impairment and reduced quality of life, little is understood about its underlying mechanisms or modulating factors. Women commonly experience exacerbation of other (non-fatigue related) psychiatric symptoms during the luteal phase of the menstrual cycle, and report greater fatigue prevalence compared to men. It is therefore plausible that subjective fatigue may similarly fluctuate across the menstrual cycle. Here we compared physical and mental fatigue in the early-follicular (lower ovarian hormones) and mid-luteal (higher ovarian hormones) phases of a single menstrual cycle, while controlling for sleep disruption, in women with (n = 18) and without (non-anxious; n = 20) generalised anxiety disorder (GAD). As expected, women with GAD reported greater physical and mental fatigue than healthy women. Further, although there were no changes in physical fatigue from the early-follicular to mid-luteal phases in both groups, mental fatigue in non-anxious women increased to levels equivalent to those experienced by their GAD counterparts in the mid-luteal phase. Although salivary levels of estradiol and progesterone increased from the early-follicular to mid-luteal phase, hormones did not significantly predict fatigue in either phase. These findings are consistent with the exacerbations of state anxiety and mood disturbance recognised to occur in the luteal phase of the menstrual cycle. We speculate that increased mental fatigue in the luteal phase may represent a vulnerable period for the development and maintenance of psychiatric disorders, potentially via compromised emotional regulation.

Gender differences in avoidance and repetitive negative thinking following symptom provocation in men and women with spider phobia.

OBJECTIVES: Women's greater prevalence of anxiety disorders compared to men is widely assumed to be partly due to gender differences in cognitive and behavioural factors that perpetuate anxiety, such as repetitive negative thinking (RNT) and avoidance. However, past studies assessing this assumption have not controlled for gender differences in baseline symptom severity, the type of stressful life experiences against which RNT and avoidance are measured, or emotional reactivity to these experiences. DESIGN: Using a two-group design, the present study controlled for these confounds by comparing avoidance and RNT in relation to a controlled symptom provocation task in spider phobic men and women with equivalent spider fear severity on the Fear of Spiders Questionnaire. METHODS: Participants engaged in a behavioural approach test (BAT) involving a live spider, during which they were assessed for avoidance (physical proximity to the spider) and subjective distress. Two weeks later, participants reported on their levels of negative affect and RNT experienced during the preceding weeks in relation to the BAT. RESULTS: Women exhibited greater avoidance and reported greater RNT than men, despite reporting comparable distress and negative affect. Gender remained a significant predictor of avoidance when accounting for distress and also remained a significant predictor of RNT when accounting for depressive symptoms and negative affect. CONCLUSIONS: These results provide in vivo evidence that heightened avoidance and RNT may perpetuate anxiety symptoms in women independently of gender differences in symptom severity, daily experiences, or emotional reactivity. PRACTITIONER POINTS: Following symptom provocation, men and women with spider phobia differ in cognitive and behavioural coping responses. Women exhibit greater avoidance and repetitive negative thinking than men, and these differences are not attributable to gender differences in symptom severity or emotional reactivity. These findings provide novel evidence for gender differences in maintaining factors that perpetuate anxiety disorders whilst accounting for confounding factors present in prior research.

The Role of Hormonal and Reproductive Status in the Treatment of Anxiety Disorders in Women.

Exposure therapy, a key treatment for anxiety disorders, can be modelled in the laboratory using Pavlovian fear extinction. Understanding the hormonal and neurobiological mechanisms underlying fear extinction in females, who are twice more likely than males to present with anxiety disorders, may aid in optimising exposure therapy outcomes in this population. This chapter will begin by discussing the role of the sex hormones, estradiol and progesterone, in fear extinction in females. We will also propose potential mechanisms by which these hormones may modulate fear extinction. The second half of this chapter will discuss the long-term hormonal, neurological and behavioural changes that arise from pregnancy and motherhood and how these changes may alter the features of fear extinction in females. Finally, we will discuss implications of this research for the treatment of anxiety disorders in women with and without prior reproductive experience.

d-Cycloserine and estradiol enhance fear extinction in nulliparous but not primiparous female rats.

Female reproductive experience has been shown to alter the hormonal, neurobiological and behavioural features of fear extinction, which is the laboratory basis of exposure therapy. This raises uncertainties as to whether pharmacological agents that enhance fear extinction in reproductively inexperienced females are equally effective in reproductively experienced females. The aim of the current study was therefore to compare the effects of two pharmacological enhancers of fear extinction, d-cycloserine (DCS) and estradiol, between nulliparous (virgin) and primiparous (reproductively experienced) female rats. In Experiment 1, nulliparous and primiparous females received systemic administration of either DCS or saline immediately after extinction training, and were tested for extinction recall the following day. DCS enhanced extinction recall in nulliparous females that showed low levels of freezing at the end of extinction training, but not among those that showed high levels of freezing at the end of extinction training. DCS did not enhance fear extinction in primiparous females, regardless of their level of freezing at the end of extinction training. In Experiment 2, nulliparous and primiparous female rats received systemic administration of either estradiol or vehicle prior to extinction training. Estradiol enhanced extinction recall among nulliparous females, but not primiparous females. Increasing the dose of estradiol administered prior to extinction training did not alter the outcomes in primiparous females (Experiment 3). Together, these findings suggest that reproductive status may be an important individual difference factor associated with the response to pharmacological modulators of extinction in rats. The implications of these findings for the pharmacological augmentation of exposure therapy in clinical populations are discussed.

The impact of chronic fluoxetine on conditioned fear expression and hippocampal FGF2 in rats: Short- and long-term effects.

Phenotypic differences in conditioned fear expression may be a marker of vulnerability to the development of anxiety disorders. Hippocampal FGF2 correlates negatively with conditioned fear expression, and antidepressants, the first-line pharmacological treatment for anxiety, increase hippocampal FGF2. In the present study, we assessed whether treatment with the selective serotonin reuptake inhibitor fluoxetine reduces conditioned fear expression in rats that naturally express lower (Low fear) or higher (High fear) levels of fear following a single-trial conditioning session. Experiment 1 demonstrated that phenotypic differences in fear expression were highly stable over a two-week interval. Experiment 2 demonstrated that two weeks of fluoxetine treatment (administered via drinking water) reduced conditioned fear expression in both Low and High fear rats. Experiment 3 demonstrated that two weeks of fluoxetine reduced conditioned fear expression even when treatment commenced two weeks after fear conditioning, but not when conditioned fear was assessed following a two-week drug-free washout period. Additionally, fluoxetine increased hippocampal FGF2 levels relative to vehicle-treated rats, but only when measured immediately after fluoxetine treatment, and not two weeks after treatment termination. Together, these results provide further indirect evidence that endogenous hippocampal FGF2 may mediate individual differences in conditioned fear expression. They also suggest that fluoxetine may be effective in reducing conditioned fear expression in both vulnerable and resilient populations when administered immediately, or sometime after, aversive experiences, but these effects do not persist once treatment is terminated.

Postnatal stress is associated with impaired fear conditioning and extinction, and heightened hippocampal fibroblast growth factor 2, in mother rats.

Rats exposed to early-life maternal separation (MS) exhibit later alterations in fear conditioning and impairments in fear extinction. As MS creates long-lasting anxiety in the mother, the present study assessed the influence of MS on fear conditioning and extinction in mother rats. It also examined whether estrous cycle effects on extinction, which are robust in nulliparous rats, but abolished in primiparous rats, re-emerge after MS. Following parturition, pups were removed from their mothers for 3 h daily from postpartum day 2-14 (MS), or remained housed with their mothers (standard reared condition, SR). Pups were weaned at postpartum day 24, and three months later, mothers received fear conditioning, extinction training, and test for extinction recall over three days. Extinction training took place during Proestrus (high estradiol and progesterone) or Metestrus (low estradiol and progesterone). Similar to past findings in non-stressed mothers, estrous cycle was not associated with conditioned fear expression (indexed by fear responses at the start of extinction training) or extinction recall in either MS or SR mothers. However, MS mothers exhibited weaker conditioned fear expression and impaired extinction recall, relative to SR mothers. Hippocampal fibroblast growth factor-2, a neurotrophin involved in stress regulation and fear expression, was elevated in MS relative to SR mothers. These results indicate that postnatal stress has long-lasting consequences for neural and behavioral systems involved in fear learning and inhibition without altering the involvement of ovarian hormones in these processes.

Effects of systemic estradiol on fear extinction in female rats are dependent on interactions between dose, estrous phase, and endogenous estradiol levels.

Administering estradiol to females during periods of low endogenous estradiol enhances their ability to extinguish fear, the laboratory basis of exposure therapy for anxiety disorders. It has therefore been proposed that estradiol could be a useful adjunct to enhance exposure therapy outcomes. The present study aimed to clarify the boundary conditions under which estradiol could be used for this purpose, by assessing whether the impact of estradiol, administered systemically prior to extinction training, differs depending on dose and estrous phase in adult female rats. Results demonstrated that in rats extinguished during metestrus (naturally low estradiol), a low dose of estradiol reduced freezing during extinction training and augmented extinction recall the following day, whereas a high dose of estradiol had no effect on either extinction training or recall. In rats extinguished during proestrus (naturally high estradiol), a high dose of estradiol impaired extinction recall, whereas a low dose of estradiol had no effect, or impairing effects, on extinction recall in different experiments. A subsequent analysis revealed that estradiol-treated proestrus rats that exhibited impaired extinction recall had significantly higher pre-treatment serum estradiol levels than those that exhibited good extinction recall. Together, these results indicate that systemically administered estradiol interacts with endogenous estradiol to produce an inverted U shaped dose effect on fear extinction, where low and high estradiol levels lead to poor extinction recall, and moderate estradiol levels lead to good extinction recall. These results highlight potential limitations to the use of estradiol as an adjunct to exposure therapy in clinical settings.

Individual differences in fear extinction and anxiety-like behavior.

There is growing appreciation for the substantial individual differences in the acquisition and inhibition of aversive associations, and the insights this might give into identifying individuals particularly vulnerable to stress and psychopathology. We examined whether animals that differed in rate of extinction (i.e., Fast versus Slow) were different in their response to an acute stress in adulthood or following a chronic stress that occurred either early or later in life. We found that Slow Extinguishers had significantly poorer extinction retention than Fast Extinguishers, but an acute stressor did not differentially affect anxiety-like behavior in the two groups. Further, while exposure to chronic stress in adulthood did not impact on the extinction phenotypes or anxiety-like behavior, exposure to chronic stress early in life affected both extinction retention and anxiety-like behavior. These findings have implications for the development of a more nuanced approach to identifying those most at risk of anxiety disorders.

Individual differences in the expression of conditioned fear are associated with endogenous fibroblast growth factor 2.

These experiments examined the relationship between the neurotrophic factor fibroblast growth factor 2 (FGF2) and individual differences in the expression of conditioned fear. Experiments 1 and 2 demonstrated that rats naturally expressing low levels of contextual or cued fear have higher levels of hippocampal FGF2 relative to rats that express high levels of conditioned fear and nonconditioned rats. Experiment 3 demonstrated that hippocampal FGF2 is not increased in rats that exhibit pharmacological-induced amnesia of conditioned fear. Together, these experiments provide evidence that FGF2 may be an endogenous regulator of fear responses to conditioned stimuli.

Estradiol levels in women predict skin conductance response but not valence and expectancy ratings in conditioned fear extinction.

Anxiety disorders are more prevalent in women than men. One contributing factor may be the sex hormone estradiol, which is known to impact the long term recall of conditioned fear extinction, a laboratory procedure that forms the basis of exposure therapy for anxiety disorders. To date, the literature examining estradiol and fear extinction in humans has focused primarily on physiological measures of fear, such as skin conductance response (SCR) and fear potentiated startle. This is surprising, given that models of anxiety identify at least three important components: physiological symptoms, cognitive beliefs, and avoidance behavior. To help address this gap, we exposed women with naturally high (n=20) or low estradiol (n=19), women using hormonal contraceptives (n=16), and a male control group (n=18) to a fear extinction task, and measured SCR, US expectancy and CS valence ratings. During extinction recall, low estradiol was associated with greater recovery of SCR, but was not related to US expectancy or CS evaluation. Importantly, women using hormonal contraceptives showed a dissociation between SCR and cognitive beliefs: they exhibited a greater recovery of SCR during extinction recall, yet reported similar US expectancy and CS valence ratings to the other female groups. This divergence underscores the importance of assessing multiple measures of fear when examining the role of estradiol in human fear extinction, especially when considering the potential of estradiol as an enhancement for psychological treatments for anxiety disorders.