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Specific features of stressful experiences, interpersonal sensitivity, and biological stress mediators in children and adolescents

University of British Columbia

This thesis examines the associations between stressful experiences and biological mediators in young people, with an emphasis on specific features of the stressor (such as duration and emotion-eliciting qualities) and the moderating role of dispositional interpersonal sensitivity. Study 1 examined the effects of major life events, chronic interpersonal stress, and the interaction between the two among 104 adolescent women. The biological outcomes were cortisol output, the expression of glucocorticoid receptor (GR) mRNA, C-reactive protein (CRP), insulin, and glucose. Results indicated that neither life events nor chronic interpersonal stress was significantly associated with biological outcomes. However, adolescents who experienced the combination of a major life event and higher levels of chronic interpersonal stress showed increased cortisol output and decreased expression of GR mRNA. This indicates that the simultaneous exposure to both acute and chronic stress may be particularly detrimental. Study 2 aimed to replicate these findings among 71 youth with asthma. This study followed participants over 2 years. Life stress, asthma-relevant immune activity, and daily asthma symptoms were measured every 6 months. Findings were analyzed using hierarchical linear modeling (HLM). Similar to the study 1 findings, youth who were double-exposed to a major life event and chronic family stress showed increased production of asthma-relevant cytokines and increased symptom expression. Finally, study 3 examined the interaction between interpersonal sensitivity and life event dimensions of loss, danger, and humiliation among 144 adolescent women. Study outcomes included markers of early cardiovascular risk, such as blood pressure and indicators of systemic inflammation (serum CRP, serum interleukin-6, and stimulated IL-6). Life stress dimensions and biological outcomes were measured every 6 months over 2.5 years. HLM analyses indicated that interpersonal sensitivity moderated the relations of danger events to CRP and diastolic blood pressure, such that the biological response was amplified among interpersonally sensitive adolescents. Interpersonal sensitivity also interacted with loss events, and adolescents high on interpersonal sensitivity showed increased production of the pro-inflammatory cytokine IL-6 in the aftermath of major loss. Overall, findings indicate that stressor impact is a complex phenomenon that depends on specific properties of the stressor, as well as dispositional factors like interpersonal sensitivity.

Text

2010-10-22

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/29453

Psychology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/