Effects of stress throughout the lifespan on the brain, behaviour and cognition.
ABSTRACT Chronic exposure to stress hormones, whether it occurs during the prenatal period, infancy, childhood, adolescence, adulthood or aging, has an impact on brain structures involved in cognition and mental health. However, the specific effects on the brain, behaviour and cognition emerge as a function of the timing and the duration of the exposure, and some also depend on the interaction between gene effects and previous exposure to environmental adversity. Advances in animal and human studies have made it possible to synthesize these findings, and in this Review a model is developed to explain why different disorders emerge in individuals exposed to stress at different times in their lives.
Full-textDOI: · Available from: Christine Heim, Aug 16, 2014
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ABSTRACT: Background Biological sex differences and socio-cultural gender diversity influence endocrine stress reactivity. While numerous studies have shown that men typically activate stronger stress responses than women when exposed to laboratory-based psychosocial stressors, it remains unclear whether sexual orientation further modulates stress reactivity. Given that lesbian, gay, and bisexual (LGB) individuals frequently report heightened distress due to stigma-related stressors, we investigated whether cortisol stress reactivity differs between LGBs and heterosexuals in response to a well-validated psychosocial stressor. Methods Eighty-seven healthy adults (mean age 25 years) were grouped according to their biological sex and their gendered sexual orientation: lesbian/bisexual women (n = 20), heterosexual women (n = 21), gay/bisexual men (n = 26), and heterosexual men (n = 20). Ten salivary cortisol samples were collected throughout a two-hour afternoon visit involving exposure to the Trier Social Stress Test modified to maximize between-sex differences. Results Relative to heterosexual women, lesbian/bisexual women showed higher cortisol stress reactivity 40 minutes post stressor. In contrast, gay/bisexual men displayed lower overall cortisol concentrations throughout testing compared to heterosexual men. Main findings were significant while adjusting for sex hormones (estradiol-progesterone ratio in women and testosterone in men), age, self-esteem, and disclosure status (whether LGB participants had completed their ‘coming out’). Conclusions Our results provide novel evidence for gender-based modulation of cortisol stress reactivity based on sexual orientation that goes beyond well-established between-sex differences. This raises several important avenues for future research related to the physiological functioning of LGB populations and gender diversity more broadly.Biological Psychiatry 08/2014; 77(7). DOI:10.1016/j.biopsych.2014.08.013 · 9.47 Impact Factor
- Animal Behaviour 07/2015; 105. DOI:10.1016/j.anbehav.2015.03.028 · 3.07 Impact Factor
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ABSTRACT: Exposures to various types of early life stress can be robust predictors of the development of psychiatric disorders, including depression and anxiety. The objective of the current study was to investigate the roles of the translationally relevant targets of central vasopressin, oxytocin, ghrelin, orexin, glucocorticoid, and the brain-derived neurotrophic factor (BDNF) pathway in an early chronic social stress (ECSS) based rodent model of postpartum depression and anxiety. The present study reports novel changes in gene expression and extracellular signal related kinase (ERK) protein levels in the brains of ECSS exposed rat dams that display previously reported depressed maternal care and increased maternal anxiety. Decreases in oxytocin, orexin, and ERK proteins, increases in ghrelin receptor, glucocorticoid and mineralocorticoid receptor mRNA levels, and bidirectional changes in vasopressin underscore related work on the adverse long-term effects of early life stress on neural activity and plasticity, maternal behavior, responses to stress, and depression and anxiety-related behavior. The differences in gene and protein expression and robust correlations between expression and maternal care and anxiety support increased focus on these targets in animal and clinical studies of the adverse effects of early life stress, especially those focusing on depression and anxiety in mothers and the transgenerational effects of these disorders on offspring. Copyright © 2015 Elsevier B.V. All rights reserved.Neuropeptides 05/2015; DOI:10.1016/j.npep.2015.05.002 · 2.55 Impact Factor