Ilona S. Yim

Attenuation of maternal psychophysiological stress responses and the maternal cortisol awakening response over the course of human pregnancy

The effects of maternal stress during pregnancy may depend, in part, on the timing in gestation of the occurrence of stress. The aim of the present study was to examine the effect of stage of gestation on maternal psychophysiological responses to stress using a standardized laboratory paradigm and on the cortisol response to awakening (CAR). A longitudinal design was employed to quantify maternal psychophysiological stress reactivity [changes in heart rate (HR), blood pressure, salivary cortisol, and psychological distress in response to the trier social stress test (TSST)] and the CAR at approximately 17 and 31 weeks gestation in a sample of 148 women. To account for the possible effects of habituation when being exposed to the same stress protocol twice, a non-pregnant comparison group (CG, N = 36) also underwent these assessments at two time points, with a comparable time interval between the assessments. In both groups, the TSST elicited significant changes in maternal HR, mean arterial pressure, and psychological distress levels but not a significant increase in cortisol levels. Among the pregnant women (pregnant group(PG)), the stressor-induced increases in HR, blood pressure, and psychological distress were significantly lower at the second (31 weeks gestation) compared to the first (17 weeks gestation) assessment of pregnancy (all p < 0.01). The maternal CAR was also significantly attenuated in later compared to earlier gestation (p = 0.003). In the CG, there were no significant differences in psychophysiological stress responses and in the CAR across the two assessments. Among pregnant women there is a progressive attenuation of psychophysiological stress responses with advancing gestation. This attenuation is unlikely to be attributable to habituation. Individual differences in the degree of attenuation of stress responses over gestation may represent a novel marker of stress susceptibility in human pregnancy.

Biological and psychosocial predictors of postpartum depression: systematic review and call for integration.

Postpartum depression (PPD) adversely affects the health and well being of many new mothers, their infants, and their families. A comprehensive understanding of biopsychosocial precursors to PPD is needed to solidify the current evidence base for best practices in translation. We conducted a systematic review of research published from 2000 through 2013 on biological and psychosocial factors associated with PPD and postpartum depressive symptoms. Two hundred fourteen publications based on 199 investigations of 151,651 women in the first postpartum year met inclusion criteria. The biological and psychosocial literatures are largely distinct, and few studies provide integrative analyses. The strongest PPD risk predictors among biological processes are hypothalamic-pituitary-adrenal dysregulation, inflammatory processes, and genetic vulnerabilities. Among psychosocial factors, the strongest predictors are severe life events, some forms of chronic strain, relationship quality, and support from partner and mother. Fully integrated biopsychosocial investigations with large samples are needed to advance our knowledge of PPD etiology.

The Perceived Stress Reactivity Scale: Measurement Invariance, Stability, and Validity in Three Countries.

There is accumulating evidence that individual differences in stress reactivity contribute to the risk for stress-related disease. However, the assessment of stress reactivity remains challenging, and there is a relative lack of questionnaires reliably assessing this construct. We here present the Perceived Stress Reactivity Scale (PSRS), a 23-item questionnaire with 5 subscales and 1 overall scale, based on an existing German-language instrument. Perceived stress reactivity and related constructs were assessed in N = 2,040 participants from the United Kingdom, the United States, and Germany. The 5-factor structure of the PSRS was found to be similar in the 3 countries. In the U.S. sample the questionnaire was applied using 2 modes of administration (paper-pencil and computerized), and measures were repeated after 4 weeks. Measurement invariance analyses demonstrated full invariance across mode of administration and partial invariance across gender and countries. Scale scores differed between countries and genders, with women scoring higher on most scales. Overall, reliability analysis suggested good stability of PSRS scores over a 4-week period, and validation analysis showed expected associations with related constructs such as self-efficacy, neuroticism, chronic stress, and perceived stress. Perceived stress reactivity was also associated with depressive symptoms and sleep. These associations were particularly strong when individuals scoring high on perceived stress reactivity were exposed to chronic stress. In sum, our findings suggest that the PSRS is a useful and easy-to-administer instrument to assess perceived stress reactivity.

Hormonal contraception use alters stress responses and emotional memory

Emotionally arousing material is typically better remembered than neutral material. Since norepinephrine and cortisol interact to modulate emotional memory, sex-related influences on stress responses may be related to sex differences in emotional memory. Two groups of healthy women - one naturally cycling (NC women, n=42) and one using hormonal contraceptives (HC women, n=36) - viewed emotionally arousing and neutral images. Immediately after, they were assigned to Cold Pressor Stress (CPS) or a control procedure. One week later, participants received a surprise free recall test. Saliva samples were collected and later assayed for salivary alpha-amylase (biomarker for norepinephrine) and cortisol. Compared to NC women, HC women exhibited significantly blunted stress hormone responses to the images and CPS. Recall of emotional images differed between HC and NC women depending on noradrenergic and cortisol responses. These findings may have important implications for understanding the neurobiology of emotional memory disorders, especially those that disproportionately affect women.

Salivary cortisol responses to a psychosocial laboratory stressor and later verbal recall of the stressor: The role of trait and state rumination

This study investigated whether trait rumination predicts greater increases in salivary cortisol concentration and delayed recovery in response to a standardized, acute laboratory psychosocial stressor (modified Trier Social Stress Test). It also tested whether trait and state rumination predict reactivation of the cortisol response during later verbal recall of the stressor. Fifty-nine undergraduates (31 females; 28 males) completed the stress protocol and returned 2 weeks later for a surprise interview about the first session, conducted in either a supportive or unsupportive context. Participants completed a measure of trait rumination and reported negative thoughts about the stressor in the 2 weeks between sessions (state rumination). Trait rumination was associated with greater reactivity of salivary cortisol level and delayed recovery from the stressor, F(1,310) = 6.77, p < 0.001. It also predicted greater cortisol reactivity when recalling the stressor, but only for males in the unsupportive interview context, F(2,119) = 7.53, p < 0.001. This effect was heightened for males who also scored high on state rumination, F(2,119) = 7.53, p < 0.001. Rumination was not associated with cortisol responses to the interviews in females. The findings indicate that rumination may play a role in prolonging cortisol stress responses through delayed recovery and reactivation and that rumination disposition and the context of stressor recall are important in understanding the rumination–cortisol response association.

The symphonic structure of childhood stress reactivity: patterns of sympathetic, parasympathetic, and adrenocortical responses to psychological challenge.

Despite widespread recognition that the physiological systems underlying stress reactivity are well coordinated at a neurobiological level, surprisingly little empirical attention has been given to delineating precisely how the systems actually interact with one another when confronted with stress. We examined cross-system response proclivities in anticipation of and following standardized laboratory challenges in 664 4- to 14-year-olds from four independent studies. In each study, measures of stress reactivity within both the locus coeruleus-norepinephrine system (i.e., the sympathetic and parasympathetic branches of the autonomic nervous system) and the corticotrophin releasing hormone system (i.e., the hypothalamic-pituitary-adrenal axis) were collected. Latent profile analyses revealed six distinctive patterns that recurred across the samples: moderate reactivity (average cross-system activation; 52%-80% of children across samples), parasympathetic-specific reactivity (2%-36%), anticipatory arousal (4%-9%), multisystem reactivity (7%-14%), hypothalamic-pituitary-adrenal axis specific reactivity (6%-7%), and underarousal (0%-2%). Groups meaningfully differed in socioeconomic status, family adversity, and age. Results highlight the sample-level reliability of childrens neuroendocrine responses to stress and suggest important cross-system regularities that are linked to development and prior experiences and may have implications for subsequent physical and mental morbidity.

Trait and state perseverative cognition and the cortisol awakening response

Perseverative cognition (i.e., rumination, worry) may amplify or maintain cortisol stress responses. The present study examined the effects of trait and state perseverative cognition (PC) on the cortisol awakening response (CAR). We hypothesized that trait PC and state (prior days) PC would be associated with greater CARs. Undergraduates scoring high (N=77) and low (N=42) on trait PC were included. Participants reported worries about upcoming events and ruminations on past events that occurred throughout the day as a measure of state PC. The next morning, saliva samples were collected 0, 30, 45, and 60min after awakening to assess the CAR. Area under the curve (AUC) and 30-min increase (30-min Inc) were calculated to capture the salivary cortisol total output and increase relative to baseline in the hour after awakening. There was no effect of trait PC on the CAR. In contrast, reports of worrying and/or ruminating the night before predicted greater increases in cortisol concentration and total cortisol output compared to those who neither ruminated nor worried the night before. These effects were not accounted for by depressed mood, anxiety, sleep, or recent stressors. Findings suggest differential effects of trait and state PC on the CAR and highlight the importance of using proximal measures in examining individual differences in the CAR.

The effect of prenatal Hatha yoga on affect, cortisol and depressive symptoms

Perinatal depression impacts maternal and child health, and little is known about effective interventions. The effects of prenatal Hatha yoga on cortisol, affect and depressive symptoms were investigated in 51 women. Twice during pregnancy, yoga group participants reported on affect and provided a saliva sample before and after a 90-min prenatal Hatha yoga session. Corresponding measures were obtained from yoga and control group participants on days of usual activity. Depressive symptoms were assessed in pregnancy and post partum. Cortisol was lower (p < .01) and positive affect higher (p < .001) on yoga compared to usual activity days. Negative affect and contentment (p < .05) improved more in response to the yoga session. Yoga group participants showed fewer postpartum (p < .05) but not antepartum depressive symptoms than control group participants. Findings indicate that prenatal Hatha yoga may improve current mood and may be effective in reducing postpartum depressive symptoms.

Stress, Interviewer Support, and Children's Eyewitness Identification Accuracy

Few studies have investigated how stress affects eyewitness identification capabilities across development, and no studies have investigated whether retrieval context in conjunction with stress affects accuracy. In this study, one hundred fifty-nine 7- to 8- and 12- to 14-year-olds completed a high- or low-stress laboratory protocol during which they interacted with a confederate. Two weeks later, they attempted to identify the confederate in a photographic lineup. The lineup administrator behaved in either a supportive or a nonsupportive manner. Participants who experienced the high-stress event and were questioned by a supportive interviewer were most accurate in rejecting target-absent lineups. Results have implications for debates about effects of stress on eyewitness recall, how best to elicit accurate identifications in children, and developmental changes in episodic mnemonic processes.

Experimental manipulation of the Trier Social Stress Test-Modified (TSST-M) to vary arousal across development.

Reliable laboratory protocols manipulating the intensity of biobehavioral arousal for children are uncommon, and those available have minimal converging evidence of their efficacy in manipulating arousal across multiple biological systems. This report presents two studies of the efficacy of the modified Trier Social Stress Test (TSST-M). In Study 1, sixty-three 7-15-year olds, and 19 young adults (18-25 yrs) completed the TSST-M. Comparable reactivity across age groups was observed for salivary cortisol, salivary alpha-amylase (sAA), pre-ejection period (PEP) and respiratory sinus arrhythmia (RSA), whereas self-reported stress was higher in adults compared to children. In Study 2, eighty-four 7-8-year olds and eighty-six 12-15-year olds were randomly assigned to a standard or low-stress TSST-M condition. Cortisol and self-reported stress responses were higher in the standard compared to the low-stress condition. In contrast, sAA and PEP were higher in the low-stress condition and RSA responses were comparable between the two TSST-M conditions. In addition, age group differences emerged in Study 2, though never in conjunction with the TSST-M manipulation. To test, refine, and advance theory about the implications of stress for child development, laboratory tasks that manipulate and enable assessment of biobehavioral arousal in children are needed.