Rachel E. Bender

Stressful Life Events and Depression Symptoms: The Effect of Childhood Emotional Abuse on Stress Reactivity

OBJECTIVE Stressful life events are associated with an increase in depressive symptoms and the onset of major depression. Importantly, research has shown that the role of stress changes over the course of depression. The present study extends the current literature by examining the effects of early life stress on emotional reactivity to current stressors. METHOD In a multiwave study (N = 281, mean age = 18.76; 68% female), we investigated the proximal changes that occur in depressive symptoms when individuals are faced with life stress and whether a history of childhood emotional abuse moderates this relationship. RESULTS Results support the stress sensitivity hypothesis for early emotional abuse history. Individuals with greater childhood emotional abuse severity experienced greater increases in depressive symptoms when confronted with current dependent stressors, controlling for childhood physical and sexual abuse. CONCLUSIONS This study highlights the importance of emotional abuse as an indicator for reactivity to stressful life events.

Life stress and kindling in bipolar disorder: Review of the evidence and integration with emerging biopsychosocial theories

Most life stress literature in bipolar disorder (BD) fails to account for the possibility of a changing relationship between psychosocial context and episode initiation across the course of the disorder. According to Posts (1992) influential kindling hypothesis, major life stress is required to trigger initial onsets and recurrences of affective episodes, but successive episodes become progressively less tied to stressors and may eventually occur autonomously. Subsequent research on kindling has largely focused on unipolar depression (UD), and the model has been tested in imprecise and inconsistent ways. The aim of the present paper is to evaluate evidence for the kindling model as it applies to BD. We first outline the origins of the hypothesis, the evidence for the model in UD, and the issues needing further clarification. Next, we review the extant literature on the changing relationship between life stress and bipolar illness over time, and find that evidence from the methodologically strongest studies is inconsistent with the kindling hypothesis. We then integrate this existing body of research with two emerging biopsychosocial models of BD: the Behavioral Approach System dysregulation model, and the circadian and social rhythm theory. Finally, we present therapeutic implications and suggestions for future research.

Bipolar Spectrum - Substance Use Co-occurrence: Behavioral Approach System (BAS) Sensitivity and Impulsiveness as Shared Personality Vulnerabilities

Bipolar disorders and substance use disorders (SUDs) show high co-occurrence. One explanation for this co-occurrence may be common personality vulnerabilities involved in both. The authors tested whether high behavioral approach system (BAS) sensitivity and impulsiveness are shared personality vulnerabilities in bipolar spectrum disorders and substance use problems and their co-occurrence in a longitudinal study of 132 individuals on the bipolar spectrum and 153 control participants. At Time 1, participants completed the Behavioral Inhibition System/BAS Scales and the Impulsive Nonconformity Scale. Substance use problems were assessed via the Michigan Alcoholism Screening Test and the Drug Abuse Screening Test at 4-month intervals for 1 year. Participants with bipolar disorder had higher rates of lifetime SUDs and substance use problems during the follow-up, relative to control participants. In line with hypotheses, higher BAS sensitivity and impulsiveness predicted bipolar status and increased substance use problems prospectively. BAS total, BAS Fun Seeking, and impulsiveness mediated the association between bipolar spectrum status and prospective substance use problems, with impulsiveness as the most important mediator. High BAS sensitivity and impulsiveness may represent shared personality vulnerabilities for both disorders and may partially account for their co-occurrence.

Stressful Life Events and Depression Symptoms

OBJECTIVE Stressful life events are associated with an increase in depressive symptoms and the onset of major depression. Importantly, research has shown that the role of stress changes over the course of depression. The present study extends the current literature by examining the effects of early life stress on emotional reactivity to current stressors. METHOD In a multiwave study (N = 281, mean age = 18.76; 68% female), we investigated the proximal changes that occur in depressive symptoms when individuals are faced with life stress and whether a history of childhood emotional abuse moderates this relationship. RESULTS Results support the stress sensitivity hypothesis for early emotional abuse history. Individuals with greater childhood emotional abuse severity experienced greater increases in depressive symptoms when confronted with current dependent stressors, controlling for childhood physical and sexual abuse. CONCLUSIONS This study highlights the importance of emotional abuse as an indicator for reactivity to stressful life events.

An experiential avoidance conceptualization of depressive rumination: three tests of the model.

This study examined an experiential avoidance conceptualization of depressive rumination in 3 ways: 1) associations among questionnaire measures of rumination, experiential avoidance, and fear of emotions; 2) performance on a dichotic listening task that highlights preferences for non-depressive material; and 3) psychophysiological reactivity in an avoidance paradigm modeled after the one used by Borkovec, Lyonfields, Wiser, and Deihl (1993) in their examination of worry. One hundred and thirty-eight undergraduates completed questionnaire measures and participated in a clinical interview to diagnose current and past episodes of depression. Of those, 100 were randomly assigned to a rumination or relaxation induction condition and participated in a dichotic listening task, rumination/relaxation induction, and depression induction. Questionnaire measures confirmed a relationship between rumination status and avoidance; however, no significant effects were found in the dichotic listening task. Psychophysiological measures indicated no difference in physiological response to a depression induction among high ruminators (HR). However, low ruminators (LR) in the relaxation condition exhibited a larger IBI response than LR in the rumination condition. Overall, these results provide partial support for an avoidance conceptualization of depressive rumination. Implications of these findings are discussed.

Life events and social rhythms in bipolar spectrum disorders: an examination of social rhythm sensitivity.

OBJECTIVES To examine the presence of an underlying social rhythm sensitivity in individuals with bipolar spectrum disorders. METHODS The present study examined the impact of life events on sleep loss and social rhythm disruption in 184 individuals with bipolar spectrum disorders (BSD) compared to 197 demographically similar normal controls (NC) drawn from the Longitudinal Investigation of Bipolar Spectrum Disorders (LIBS) project. Life events data were obtained at three time points, each spaced four months apart, and included information on the intensity of the event (high or low), valence (negative or positive), and levels of sleep loss and social rhythm disruption brought about the event. We hypothesized that BSD participants would exhibit higher levels of social rhythm disruption and sleep loss than normal controls as a consequence of the same life events. RESULTS BSD participants experienced significantly more social rhythm disruption and sleep loss following all classes of life events. LIMITATIONS The cross-sectional design of this study limits the strength of the conclusions that can be drawn, primarily cause and effect relationships between social rhythms and symptoms. CONCLUSIONS Findings support the presence of an underlying social rhythm sensitivity in individuals with bipolar spectrum disorders. An additive effect of sleep loss and social rhythm disruption may contribute to subsequent mood symptomatology. Results from this study may inform early psychosocial interventions for at-risk individuals.

Generation of life events in bipolar spectrum disorders: A re‐examination and extension of the stress generation theory

The extent to which stress generation occurs in bipolar spectrum disorders (BSD) is not well understood. The present study examined whether 75 BSD participants experienced elevated rates of behavior-dependent life events, as compared with 38 normal control participants. Within the BSD group, we also examined whether depressive or hypomanic symptoms prospectively predicted increases in various types of negative and positive life events. Results indicated that BSD participants experienced overall increases in behavior-dependent events over the follow-up, as compared with normal controls. At the symptom level, the event generation process occurred in more specific event domains. Results suggest that the stress generation theory of unipolar depression can be extended to BSD and that the type of generated events may be polarity-specific.

Aggression and impulsivity as predictors of stress generation in bipolar spectrum disorders

BACKGROUND Some evidence suggests that individuals with bipolar spectrum disorders (BSD) generate stressful life events, contributing to a more severe course of disorder. A recent update to the Behavioral Approach System (BAS) dysregulation theory of BSD highlights the need to investigate anger as approach motivation. Although research has shown that individuals with BSD generate stress, it is unclear whether personality traits characteristic of BSD, such as aggression and impulsivity, are related to this stress generation. METHODS The current longitudinal study employed multilevel modeling to examine stress generation in a sample of 104 individuals with BSD and 96 healthy controls. We examined rates of BAS-deactivating, BAS-activating, and Anger-evoking life events over a period of up to 4.5 years as a function of levels of aggression and impulsivity. RESULTS Individuals with BSD reported significantly higher numbers of dependent Anger-evoking events and BAS-deactivating events, but not dependent BAS-activating events, than controls. Trait levels of hostility and impulsivity predicted all types of events, although bipolar diagnosis remained a significant predictor of BAS-deactivating and Anger-evoking events. LIMITATIONS The life events measures were not designed to assess Anger-evoking events; further research should replicate these findings and develop more finely tuned assessments of stressful anger events. In addition, the sample was not a clinical sample. CONCLUSIONS This study adds to the literature on stress generation in BSD; trait level personality differences predict stress generation, beyond bipolar diagnosis. This also further establishes the importance of including anger-evoking events in the BAS model of BSDs and stress generation.