Problematic Internet use, excessive alcohol consumption, their comorbidity and cardiovascular and cortisol reactions to acute psychological stress in a student population

Background and aims Problematic Internet use and excessive alcohol consumption have been associated with a host of maladaptive outcomes. Further, low (blunted) cardiovascular and stress hormone (e.g. cortisol) reactions to acute psychological stress are a feature of individuals with a range of adverse health and behavioural characteristics, including dependencies such as tobacco and alcohol addiction. The present study extended this research by examining whether behavioural dependencies, namely problematic Internet use, excessive alcohol consumption, and their comorbidity would also be associated with blunted stress reactivity Methods A large sample of university students (N = 2313) were screened using Internet and alcohol dependency questionnaires to select four groups for laboratory testing: comorbid Internet and alcohol dependence (N = 17), Internet dependence (N = 17), alcohol dependence (N = 28), and non-dependent controls (N = 26). Cardiovascular activity and salivary cortisol were measured at rest and in response to a psychological stress protocol comprising of mental arithmetic and public speaking tasks. Results Neither problematic Internet behaviour nor excessive alcohol consumption, either individually or in combination, were associated with blunted cardiovascular or cortisol stress reactions. Discussion It is possible that problematic Internet behaviour and excessive alcohol consumption in a student population were not related to physiological reactivity as they may not reflect ingrained addictions but rather an impulse control disorder and binging tendency. Conclusions The present results serve to indicate some of the limits of the developing hypothesis that blunted stress reactivity is a peripheral marker of the central motivational dysregulation in the brain underpinning a wide range of health and behavioural problems

Cardiovascular and Cortisol Reactions to Acute Psychological Stress Under Conditions of High Versus Low Social Evaluative Threat: Associations With the Type D Personality Construct

Objectives Social evaluative threat is an important factor in the cardiovascular response to mental stress. This study examined whether Type D personality, characterized by social inhibition and negative affectivity, is associated with an adverse cardiovascular response to a non-social and social evaluative threat. Methods A total of 2300 students were screened for Type D personality, and 130 were selected for a nonsocial stress exposure condition (31 Type D, 30 non–Type D: 52% female) or a condition high in social evaluative threat (35 Type D, 34 non–Type D: 55% female). Systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), and salivary cortisol were measured. Results Social evaluative threat resulted in higher cardiovascular responses than the nonsocial challenge (SBP, p = .001, η2 = 0.092;DBP, p = .006, η2 = 0.058;HR, p = .006, η2 = 0.059). The greatest cardiovascular stress reactions were exhibited by Type D participants in the high social evaluation condition; reflected in significant group by condition interactions for SBP (F(1,126) = 7.29, p = .008, η2 = 0.055), DBP (F(1,126) = 5.23, p = .024, η2 = 0.040), and HR (F(1,126) = 5.04, p = .027, η2 = 0.038) reactivity. Only Type Ds in the social condition mounted a positive cortisol response (F(1,33) = 5.07, p = .031, η2 = 0.133). Conclusions Type D individuals show different stress reactions depending on the social evaluative nature of the stress exposure. These findings suggest that dysregulation of the stress response in social situations potentially increases cardiovascular disease risk

Blunted cardiac stress reactors exhibit relatively high levels of behavioural impulsivity

Blunted physiological reactions to acute psychological stress are associated with a range of adverse health and behavioural outcomes. This study examined whether extreme stress reactors differ in their behavioural impulsivity. Individuals showing blunted (N = 23) and exaggerated (N = 23) cardiovascular reactions to stress were selected by screening a healthy student population (N = 276). Behavioural impulsivity was measured via inhibitory control and motor impulsivity tasks. Blunted reactors exhibited greater impulsivity than exaggerated reactors on both stop-signal, F(1,41) = 4.99, p = 0.03, ηp2 = 0.108, and circle drawing, F(1,43) = 4.00, p = 0.05, η p 2 = 0.085, tasks. Individuals showing blunted cardiovascular stress reactions are characterized by greater impulsivity which may contribute to their increased susceptibility to outcomes such as obesity and addiction

The behavioural, cognitive, and neural corollaries of blunted cardiovascular and cortisol reactions to acute psychological stress

Recent research shows that blunted cardiovascular and cortisol reactions to acute psychological stress are associated with adverse behavioural and health outcomes: depression, obesity, bulimia, and addictions. These outcomes may reflect suboptimal functioning of the brain’s fronto-limbic systems that are needed to regulate motivated behaviour in the face of challenge. In support of this, brain imaging data demonstrate fronto-limbic hypoactivation during acute stress exposure. Those demonstrating blunted reactions also show impairments of motivation, including lower cognitive ability, more rapid cognitive decline, and poorer performance on motivation-dependent tests of lung function. Persons exhibiting blunted stress reactivity display well established temperament characteristics, including neuroticism and impulsivity, characteristic of various behavioural disorders. Notably, the outcomes related to blunted stress reactivity are similar to those that define Reward Deficiency Syndrome. Accordingly, some individuals may be characterised by a broad failure in cardiovascular and cortisol responding to both stress and reward, reflecting fronto-limbic dysregulation. Finally, we proffer a model of blunted stress reactivity, its antecedents and sequelae, and identify future research priorities

Life event stress is associated with blunted cardiovascular responding to both personally salient and personally non‐salient laboratory tasks

Life event stress has been associated with blunted cardiovascular reactivity to acute psychological stress. However, recent studies have suggested that blunted reactivity to stress only arises when the laboratory tasks are not personally salient to the individual. We re-analyzed data from 136 healthy young adults where we had previously reported a negative association between life event stress and cardiovascular reactivity to two combined stressors. Participants completed a mental arithmetic task and a personally salient speech task, following a formal baseline period with Finometer-assessed cardiovascular parameters. The reanalyses examined reactivity to the verbal mental arithmetic (personally non-salient) and speech (personally salient) tasks separately and found that life event stress was negatively associated with diastolic blood pressure reactivity, to both the personally non-salient, β = −.20, p = .023, and personally salient stressors, β = −.24, p = .004. Life event stress was negatively associated with systolic blood pressure reactivity to the personally salient stressor only, β = −.20, p = .021, and was not associated with heart rate reactivity. This study provides evidence against the argument that blunted reactivity to stress emerges as a result of stressor context, with findings indicating that low reactors show lower reactivity to both personally salient and personally non-salient stress.Output Status: Forthcoming/Available Onlin

A tale of two mechanisms: A meta-analytic approach toward understanding the autonomic basis of cardiovascular reactivity to acute psychological stress: Autonomic basis of cardiovascular reactivity

A series of meta‐analyses was undertaken to determine the contributions of sympathetic and parasympathetic activation to cardiovascular stress reactivity. A literature search yielded 186 studies of sufficient quality that measured indices of sympathetic (n = 113) and/or parasympathetic activity (n = 73). A range of psychological stressors perturbed blood pressure and heart rate. There were comparable aggregate effects for sympathetic activation, as indexed by increased plasma epinephrine and norepinephrine, and shortened pre‐ejection period and parasympathetic deactivation, as indexed by heart rate variability measures. Effect sizes varied with stress task, sex, and age. In contrast to alpha‐adrenergic blockade, beta‐blockade attenuated cardiovascular reactivity. Cardiovascular reactivity to acute psychological stress would appear to reflect both beta‐adrenergic activation and vagal withdrawal to a largely equal extent

Exploring the possible mechanisms of blunted cardiac reactivity to acute psychological stress

Blunted cardiovascular reactivity to acute psychological stress has been linked to a range of adverse health and behavioral outcomes. However, the origins of blunted reactivity remain unclear. The current study aimed to explore the following possibilities: different appraisals of task stressfulness and/or difficulty, diminished task effort, or reduced physiological capacity to respond. Individuals characterized, via pre-screening, as blunted (n = 17) or exaggerated (n = 16) heart rate (HR) reactors to acute psychological stress (socially evaluative mental arithmetic) were exposed to a psychological stress, cold pressor and exercise tasks during a follow-up testing session while HR and blood pressure (BP) were measured. At follow-up, groups again mounted significantly different HR reactions to psychological stress, despite reporting similar levels of subjective stress and difficulty, and achieving similar tasks scores (measure of task effort) at both testing sessions. In response to the cold pressor and exercise blunted and exaggerated reactors displayed similar HR and BP responses. Results indicated that blunted reactors do not differ from exaggerated reactors on appraisals of task stressfulness or difficulty, or objective task effort, and do possess the physiological capacity to respond to other laboratory challenges. Other sources of blunted stress reactivity remain to be explored