Kyle W. Murdock

Integrating and Differentiating Aspects of Self-Regulation: Effortful Control, Executive Functioning, and Links to Negative Affectivity

Subdisciplines within psychology frequently examine self-regulation from different frameworks despite conceptually similar definitions of constructs. In the current study, similarities and differences between effortful control, based on the psychobiological model of temperament (Rothbart, Derryberry, & Posner, 1994), and executive functioning are examined and empirically tested in three studies (n = 509). Structural equation modeling indicated that effortful control and executive functioning are strongly associated and overlapping constructs (Study 1). Additionally, results indicated that effortful control is related to the executive function of updating/monitoring information in working memory, but not inhibition (Studies 2 and 3). Study 3 also demonstrates that better updating/monitoring information in working memory and better effortful control were uniquely linked to lower dispositional negative affect, whereas the executive function of low/poor inhibition was uniquely associated with an increased tendency to express negative affect. Furthermore, dispositional negative affect mediated the links between effortful control and, separately, the executive function of updating/monitoring information in working memory and the tendency to express negative affect. The theoretical implications of these findings are discussed, and a potential framework for guiding future work directed at integrating and differentiating aspects of self-regulation is suggested.

Executive functioning and diabetes: The role of anxious arousal and inflammation

Individuals who perform poorly on measures of the executive function of inhibition have higher anxious arousal in comparison to those with better performance. High anxious arousal is associated with a pro-inflammatory response. Chronically high anxious arousal and inflammation increase ones risk of developing type 2 diabetes. We sought to evaluate anxious arousal and inflammation as underlying mechanisms linking inhibition with diabetes incidence. Participants (N=835) completed measures of cognitive abilities, a self-report measure of anxious arousal, and donated blood to assess interleukin-6 (IL-6) and glycated hemoglobin (HbA1c). Individuals with low inhibition were more likely to have diabetes than those with high inhibition due to the serial pathway from high anxious arousal to IL-6. Findings remained when entering other indicators of cognitive abilities as covariates, suggesting that inhibition is a unique cognitive ability associated with diabetes incidence. On the basis of our results, we propose several avenues to explore for improved prevention and treatment efforts for type 2 diabetes.

Loneliness predicts self-reported cold symptoms after a viral challenge.

Objective: Loneliness is a well-established risk factor for poor physical health. Much less is known about how loneliness affects patient-reported outcomes (PROs), such as somatic symptoms, which are increasingly important for guiding symptom management and assessing quality of patient care. The current study investigates whether (a) loneliness and social isolation predict cold symptoms independent of each other, and (b) whether loneliness is a more robust risk factor than objective social isolation for experiencing cold symptoms. Method: As part of a larger parent study, 213 healthy participants completed the Short Loneliness Scale (LON) and the Social Network Index (SNI) at baseline. They were given nasal drops containing rhinovirus 39 (RV39; i.e., a common cold virus), then quarantined for 5 days during which they reported on subjective cold symptoms in addition to being monitored for objective indicators of infection. Data from 160 of the participants (who were infected with the virus) were used in the present analyses. Results: A hierarchical multiple regression revealed that baseline loneliness predicted self-reported cold symptoms over time (assessed via area under the curve), over and above demographic variables, season of participation, and depressive affect. Interestingly, social network size and diversity did not predict cold symptoms. Conclusions: These findings suggest that the perception of loneliness is more closely linked to self-reported illness symptoms than objectively measured social isolation. Assessing psychosocial factors such as loneliness when treating and evaluating the common cold could contribute to health care practitioners’ understanding of their patients’ experiences with acute illness.

The effect of self-reported health on latent herpesvirus reactivation and inflammation in an ethnically diverse sample.

Self-rated health (SRH) is a reliable predictor of health outcomes including morbidity and mortality. Immune dysregulation is one hypothesized mechanism underlying the association between SRH and health outcomes. Indeed, poorer SRH is associated with greater inflammation. The association between SRH and reactivation of latent herpesviruses is unknown, representing an important gap in the literature given that reactivation of latent herpesviruses leads to enhanced inflammation. The present study addressed this important gap in the literature by examining associations between SRH, inflammation (i.e., peripheral cytokines in the blood), and reactivation of latent herpesviruses among a sample of 1208 individuals participating in the Texas City Stress and Health Study. Participants completed a self-report measure of SRH and a blood draw. Results indicated that higher SRH was associated with lower reactivation of latent herpesviruses and inflammation. Moreover, reactivation of latent herpesviruses partially mediated the association between SRH and inflammation. Accordingly, findings add to our growing understanding of the association between SRH and immune dysfunction.

Biobehavioral Pathways to Cancer Incidence, Progression, and Quality of Life:

Cancer research within the fields of psychoneuroendocrinology and psychoneuroimmunology has made substantial progress in understanding how psychological factors impact cancer. Although the pathways by which stress “gets under the skin” to impact cancer incidence, progression, and quality of life are not yet fully understood, the answers to key questions about how stressful life events and the negative emotions they generate can impact cancer initiation, progression, and survivorship have advanced quite dramatically. In this review, we summarize the state of the science in a way that is accessible to a broad audience. We then discuss future directions in cancer research, with a focus on ways psychological science can contribute to the next generation of cancer care.

Loss and the Organization of Affect

The present studies evaluated the association between positive affect (PA) and negative affect (NA) following romantic relationship loss experiences, as well as following less stressful romantic relationship situations, given theoretical evidence that the structure of affect may differ following a relationship loss. Across two studies, evidence suggested that the association between NA and PA was more strongly inverse following romantic relationship loss experiences when compared to less stressful relationship experiences. Such findings provide important implications for the study of romantic relationship loss, as well as the treatment of psychopathology following romantic relationship loss.

Grief, depressive symptoms, and inflammation in the spousally bereaved

Grief is conceptualized by strong negative emotions, which include longing, sadness, and preoccupations with thoughts, recollections, and images of the spouse. In the initial months after the loss of a spouse, those who are widowed are at risk for cardiovascular problems and premature mortality. In the general population, depression is characterized by chronic low-grade inflammation, a key predictor of cardiovascular problems, morbidity, and mortality. Although depression and grief share similarities, they are distinct constructs. We aimed to identify if grief was related to inflammation among those who had a spouse recently die. We also sought to determine if those who are widowed and already experience elevated levels of depressive symptoms compared with the general population had higher levels of inflammation compared with those who are widowed who report fewer depressive symptoms. Ninety-nine recently bereaved individuals (M = 84.74 days since passing, SD = 18.17) completed a blood draw and psychological assessments. Proinflammatory T cell-derived cytokines were assessed, which included interferon gamma (IFN-γ), interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), IL17-A, and IL-2. Bereaved individuals with a higher grief severity (using an established cut-score) had higher levels of the proinflammatory cytokines IFN-γ, IL-6, and TNF-α than those with less grief severity. Those who experienced higher levels of depression exhibited elevated levels of proinflammatory cytokines compared with those who had lower levels of depression (using a continuous measure of depressive symptoms, as well as an established cut score). This is the first study to demonstrate that inflammatory markers can distinguish those who are widowed based on grief severity such that those who are higher on grief severity have higher levels of inflammation compared with those who are lower on grief severity. These findings also add to the broader literature on depression and inflammation by showing that even in a population with high levels of depressive symptoms, there is a positive relationship between depression and inflammation.

Inhibition is associated with metabolic syndrome and depression through inflammation

Inhibition is the ability to stop ones self from responding, or paying attention, to tempting/distracting stimuli or thoughts. Those with poor inhibition are at greater risk of depression and a variety of diseases of older adulthood than those with better inhibition. Inflammation may be a mechanism underlying these links. A total of 840 participants from the Midlife in the United States study completed a neuropsychological measure of inhibition, a self-report measure of depressive symptoms, and a blood draw. Results indicated that poor inhibition was associated with high interleukin-6 (IL-6). Inhibition was indirectly associated with metabolic syndrome incidence and depressive symptoms through IL-6. Findings suggest that IL-6 may be a mechanism linking inhibition with metabolic syndrome and depression.

Impaired mental health and low-grade inflammation among fatigued bereaved individuals

BACKGROUND Fatigue is a common symptom in stressed individuals. Bereavement is a major life event that has been associated with impaired mental health. Little research has investigated the prevalence of fatigue and its inflammatory correlates in bereaved individuals. OBJECTIVES To assess fatigue prevalence and its relationship with mental health outcomes and markers of inflammation, as indexed by C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in bereaved individuals. METHODS Seventy-eight-bereaved adults were examined for fatigue (SF-36 energy/vitality scale), perceived stress (PSS), depression (CES-D), sleep quality (PSQI), pain (SF-36 pain scale), and general health (SF-36 general), and their serum levels of CRP, IL-6 and TNF-α were measured. Group differences between fatigued versus non-fatigued individuals were estimated using analysis of covariance (ANCOVA), with adjustment for body mass index (BMI). RESULTS Fatigued bereaved individuals (33%; SF-36 energy/vitality score 0-45) had significantly higher CRP levels (p < .05) as compared to non-fatigued bereaved individuals and reported higher levels of pain (p < .001), greater stress (p < .001), depression (p < .001), and sleeping problems (p < .001), as well as poorer social functioning (p < .001) and general health (p < .001) than those in the non-fatigued group. No group differences were found for IL-6 and TNF-α. CONCLUSIONS Fatigued bereaved individuals showed elevated systemic inflammation as measured by CRP in comparison to non-fatigued bereaved individuals. They were also more likely to report mental health problems that co-occur with fatigue in the context of immune activation. Continued research is needed to help clarify the involvement of inflammatory markers in the development of fatigue in a larger sample of bereaved adults.

Maternal and Paternal Predictors of Child Depressive Symptoms: An Actor-Partner Interdependence Framework

Family members are theorized to influence each other via transactional or systems related processes; however, the literature is limited given its focus on mother–child relationships and the utilization of statistical approaches that do not model interdependence within family members. The current study evaluated associations between self-reported parental affect, parenting behavior, and child depressive symptoms among 103 mother–father–child triads. Children ranged in age from 8 to 12 years. Higher maternal negative affect was associated with greater maternal and paternal harsh/negative parenting behavior. While maternal negative affect was directly associated with child depressive symptoms, paternal negative affect was indirectly associated with child depressive symptoms via paternal harsh/negative behavior. In a separate model, maternal positive affect was indirectly associated with child depressive symptoms via maternal supportive/positive behavior. These results highlight the importance of simultaneously modeling maternal and paternal characteristics as predictors of child depressive symptoms.