Panic Disorder in Women

Impact of the estrous cycle on brain monoamines and behavioral and respiratory responses to CO2 in mice

The prevalence of panic disorder is two to four times higher in women compared to that in men, and hormonal changes during the menstrual cycle play a role in the occurrence of panic attacks. Here, we investigated the effect of the estrous cycle on the ventilatory and behavioral responses to CO2 in mice. Female mice in proestrus, estrus, metestrus, or diestrus were exposed to 20% CO2, and their escape behaviors, brain monoamines, and plasma levels of 17β-estradiol (E2) and progesterone (P4) were measured. Pulmonary ventilation (V̇E), oxygen consumption (V̇O2), and body core temperature (TB) were also measured during normocapnia followed by CO2. Females exposed to 20% CO2 exhibited an escape behavior, but the estrous cycle did not affect this response. Females in all phases of the estrous cycle showed higher V̇E and lower TB during hypercapnia. In diestrus, there was an attenuation of CO2-induced hyperventilation with no change in V̇O2, whereas in estrus, this response was accompanied by a reduction in V̇O2. Hypercapnia also increased the concentration of plasma P4 and central DOPAC, the main dopamine metabolite, in all females. There was an estrous cycle effect on brainstem serotonin, with females in estrus showing a higher concentration than females in the metestrus and diestrus phases. Therefore, our data suggest that hypercapnia induces panic-related behaviors and ventilatory changes that lead to an increase in P4 secretion in female mice, likely originating from the adrenals. The estrous cycle does not affect the behavioral response but interferes in the ventilatory and metabolic responses to CO2 in mice.

Sex differences in emotional and physiological responses to the Trier Social Stress Test

Women are more likely than men to be diagnosed with depression and anxiety-related disorders, and it has been hypothesized that this difference is related to sex differences in stress reactivity. Women typically report higher levels of negative affect than men in response to psychosocial stressors, but the evidence for sex differences in physiological reactivity to stressful situations is not consistent. The present study sought to expand this work by evaluating sex differences in reactivity to a social stress challenge across neuroendocrine, autonomic and affective response domains. Participants (32 women, 30 men) completed a standardized psychosocial stress challenge (i.e., the Trier Social Stress Test (TSST)), during which several physiological (e.g., cortisol reactivity, heart rate) and psychological (e.g., depression, irritability, anger, fear) measures were assessed. The findings demonstrated that cortisol reactivity and the magnitude of autonomic responding failed to reliably discriminate between women and men. However, women reported more fear, irritability, confusion and less happiness immediately following the TSST compared to men. The broader implications of these results and how they relate to sex differences in the etiology and clinical presentation of anxiety and mood disorders are discussed.

Are we there yet? A review of gender comparisons in three behavioral journals through the 20th century

Despite overwhelming evidence that gender plays a significant role in the course of numerous psychological disorders, researchers have historically neglected to address gender similarities and differences in their research. Previous reviews of the psychological literature have indicated that personality, psychotherapy, and behavioral psychology journals have published few studies that focus on gender comparisons. The current review examined published articles in three prominent behavioral psychology journals--Behavior Therapy, Behavior Modification, and Behaviour Research and Therapy--from their inception through 2001. Raters coded each article (N=4,635) for gender content in the title or abstract, analyses of gender differences, and discussion of gender. Overall, very few articles focused on gender content in the title, abstract, or discussion or analyzed data by gender. Implications of these results and suggestions for enhancing attention to gender comparisons are discussed.

Sex differences in response to a panicogenic challenge procedure: An experimental evaluation of panic vulnerability in a non-clinical sample

Epidemiological studies show that women are twice as likely as men to develop panic disorder (PD) during their lifetimes. Data from retrospective studies also suggest that women are more distressed by panic and other negative emotional states than men, and that this tendency may precede the development of PD. The present prospective study sought to expand this work by evaluating sex differences in the predisposition to panic in individuals without PD or other forms of psychopathology. Participants (N=96; 52 women) were exposed to 12 panicogenic inhalations of 20% CO2-enriched air while physiological (e.g., heart rate, electrodermal response, Frontalis EMG) and self-report (e.g., subject distress, fear, frequency and severity of DSM-IV panic symptoms) response domains were monitored. As expected, magnitude of autonomic responding failed to reliably discriminate between women and men. Yet, women reported more fear and panic immediately following the challenge procedure relative to men, and this sex difference persisted when assessed again 30 min post-challenge. Implications of these results are discussed broadly in the context of biopsychosocial accounts of sex differences in the clinical presentation of PD.

Gender differences in anxiety-related traits in patients with panic disorder

This study examined gender differences in anxiety-related personality traits in patients with panic disorder with or without agoraphobia (PD+/-AG). Outpatients (101 total) with SCID confirmed PD+/-AG completed the Anxiety Sensitivity Index (ASI), the Trait form of the State-Trait Anxiety Inventory (STAI-T), the NEO Personality Inventory Revised (NEO PI-R), and the Retrospective Self-Report of Inhibition (RSRI) as part of their assessment. Significant gender differences were not detected for the total ASI scores. Females scored significantly higher than males on the Physical Concerns subscale of the ASI, whereas males scored significantly higher than women on the Social Concerns subscale. Women scored higher than men on the Extraversion scale of the NEO PI-R as well as on certain subscales of this domain. Although a significant gender difference was not detected on the Neuroticism subscale, men scored higher on the angry hostility and depression facets of this trait. Significant gender differences were not found for the STAI-T or the RSRI. These findings suggest that gender differences exist among patients with PD+/-AG in the feared consequences of anxiety symptoms as well as in the personality characteristics of extraversion.

Is premenstrual dysphoria a variant of panic disorder? A review

Patients with premenstrual dysphoric disorder (PMDD) and patients with panic disorder (PD) both experience high rates of panic attacks in laboratory panic provocation studies. Recently, this shared elevated rate of challenge-induced panic has received increasing attention. Researchers have suggested that PMDD and panic disorder may share a pathophysiological or psychobiological link. The purpose of this paper is to review the findings from PMDD challenge studies and the theories advanced to connect PMDD to panic disorder. Taken together, the results of the PMDD challenge studies confirm that agents that incite panic in PD patients do so as well in PMDD women. This shared elevated challenge-induced panic cannot be accounted for by explanations such as a history of PD in PMDD women. None of the physiological theories as currently expressed--suffocation false alarm, gamma-aminobutyric acid (GABA), noradrenergic, serotonergic, and cholecystokinin--yet provides a compelling candidate to account for shared elevated challenge-induced panic in PD and PMDD patients. Psychological perspectives on panic emphasize that bodily sensations themselves can cause fear. Researchers have yet to apply several influential psychological approaches--conditioning, catastrophic misinterpretation, and anxiety sensitivity--to PMDD patients. Because psychological factors influence anxious responding in challenge studies, the search for the biological abnormality best accounting for PMDD panic might benefit from a reframing of the question to one that considers the psychological perspective as well.

Panic disorder in menopause: a case control study

OBJECTIVE

The course of panic disorder (PD) is often influenced by the different phases of the female reproductive cycle. The aim of this study is to assess PD in the climacteric stage and single out possible correlations between symptoms of PD and clinical and demographic variables in order to identify possible risk factors.

METHOD

Forty-five women between 40 and 60 years of age was assessed through the SCL-90, the SCID, a "Climacteric Symptoms Questionnaire" (CSQ) devised to evaluate psychological symptoms typically associated with menopause, the Kupperman Index for the analysis of climacteric symptoms, and plasma level of allopregnanolone (ALLO).

RESULTS

PD results in eight patients (18%). This group does not differ from the controls as far as socio-demographic data is concerned, but exhibits significantly higher values in the Kupperman Index, the SCL-90 total, and the CSQ. The plasma levels of ALLO correlate significantly inversely with the total of CSQ and, in any case, negatively with the other variables analysed.

CONCLUSIONS

PD may arise and worsen with menopause, in correlation with greater severity of the climacteric syndrome in its physical and psychological symptoms.