Is personality associated with dementia risk? A meta-analytic investigation

This study provides a quantitative synthesis of the prospective associations between personality traits (neuroticism, extraversion, openness, agreeableness, conscientiousness) and the risk of incident Alzheimer’s disease and related dementias. We conducted five separate meta-analyses with 8–12 samples (N = 30,036 to 33,054) that were identified through a systematic literature search following the MOOSE guidelines. Higher neuroticism (HR = 1.24, 95% CI [1.17, 1.31]) and lower conscientiousness (HR = 0.77, 95% CI [0.73, 0.81]) were associated with increased dementia risk, even after accounting for covariates such as depressive symptoms. Lower extraversion (HR = 0.92, 95% CI [0.86, 0.97]), openness (HR = 0.91, 95% CI [0.86, 0.96]), and agreeableness (HR = 0.90, 95% CI [0.83, 0.98]) were also associated with increased risk, but these associations were less robust and not significant in fully adjusted models. No evidence of publication bias was found. The strength of associations was unrelated to publication year (i.e., no evidence of winner’s curse). Meta-regressions indicated consistent effects for neuroticism, openness, and conscientiousness across methods to assess dementia, dementia type, follow-up length, sample age, minority, country, and personality measures. The association of extraversion and agreeableness varied by country. Our findings indicate robust associations of neuroticism and conscientiousness with dementia risk.     

Role of negative affects in pathophysiology and clinical expression of irritable bowel syndrome

Irritable bowel syndrome(IBS)is regarded as a multifactorial disease in which alterations in the brain-gut axis signaling play a major role.The biopsychosocial model applied to the understanding of IBS pathophysiology assumes that psychosocial factors,interacting with peripheral/central neuroendocrine and immune changes,may induce symptoms of IBS,modulate symptom severity,influence illness experience and quality of life,and affect outcome.The present review focuses on the role of negative affects,including depression,anxiety,and anger,on pathogenesis and clinical expression of IBS.The potential role of the autonomic nervous system,stress-hormone system,and immune system in the pathophysiology of both negative affects and IBS are taken into account.Psychiatric comorbidity and subclinical variations in levels of depression,anxiety,and anger are further discussed in relation to the main pathophysiological and symptomatic correlates of IBS,such as sensorimotor functions,gut microbiota,inflammation/immunity,and symptom reporting.     

Chronic pain and sensorimotor deficits following peripheral nerve injury

Following upper limb peripheral nerve transection and surgical repair (PNIr) patients frequently exhibit sensory and motor deficits, but only some develop chronic neuropathic pain. Thus, the sensorimotor outcome of PNIr may be impacted by individual factors. Therefore, our aims were to determine if patients with chronic neuropathic pain (PNI-P) following PNIr (1) are distinguished from patients without pain (PNI-NP) and healthy controls (HCs) by the psychological factors of pain catastrophizing, neuroticism or extraversion, and (2) exhibit more severe sensorimotor deficits than patients who did not develop chronic pain (PNI-NP). Thirty-one patients with complete median and/or ulnar nerve transection (21 PNI-NP, 10 PNI-P) and 21 HCs completed questionnaires to assess pain characteristics, pain catastrophizing, neuroticism and extraversion and underwent sensorimotor evaluation. Nerve conduction studies revealed incomplete sensorimotor peripheral recovery based on abnormal sensory and motor latency and amplitude measures in transected nerves. The patients also had significant deficits of sensory function (two-point discrimination and vibration, touch, and warmth detection), sensorimotor integration, and fine motor dexterity. Compared to PNI-NP patients, PNI-P patients had higher vibration detection thresholds, performed worse on sensory-motor integration tasks, had greater motor impairment, and showed more impaired nerve conduction. Furthermore, PNI-P patients had reduced cold pain tolerance, elevated pain intensity and unpleasantness during the cold pressor test, and they scored higher on neuroticism and pain-catastrophizing scales. These data demonstrate that chronic neuropathic pain following PNIr is associated with impaired nerve regeneration, profound sensorimotor deficits and a different psychological profile that may be predictive of poor recovery after injury.     

Association of mental health with the risk of coronary artery disease in patients with diabetes: A mendelian randomization study

Background and aimsObservational studies have shown an association between mental health and coronary artery disease (CAD) in patients with diabetes. Nevertheless, whether these associations are causal is still unknown. In this two-sample Mendelian randomization (MR) study, we aimed to assess the causality between mental health and CAD in patients with diabetes.Methods and resultsSingle-nucleotide polymorphisms (SNPs) associated with: depression (807,553 individuals), anxiety (83,556 individuals) and neuroticism (329,821 individuals) were identified from the largest genome-wide association studies (GWAS). Summary-level data for CAD were extracted from the recently published GWAS of 15,666 diabetic patients (3968 CAD cases and 11,696 controls). The inverse-variance weighted (IVW) method was used for the main analysis. Sensitivity analyses included weighted median, maximum likelihood, and the MR-Egger method. Genetic liability to depression was significantly associated with a higher risk of CAD in patients with diabetes (odds ratio [OR], 1.286; 95%CI,1.018–1.621;p = 0.035). For anxiety and neuroticism, no causal association with CAD in patients with diabetes was observed. Consistent results were obtained in most sensitivity analyses.ConclusionsThis MR study provides genetic evidence that depression is a potential risk factor for CAD in patients with diabetes. However, anxiety and neuroticism were not causally associated with CAD in patients with diabetes. Mental health treatments should be enhanced to prevent CAD in patients with diabetes.     

Personality and physiological reactions to acute psychological stress

Stable personality traits have long been presumed to have biological substrates, although the evidence relating personality to biological stress reactivity is inconclusive. The present study examined, in a large middle aged cohort (N = 352), the relationship between key personality traits and both cortisol and cardiovascular reactions to acute psychological stress. Salivary cortisol and cardiovascular activity were measured at rest and in response to a psychological stress protocol comprising 5 min each of a Stroop task, mirror tracing, and a speech task. Participants subsequently completed the Big Five Inventory to assess neuroticism, agreeableness, openness to experience, extraversion, and conscientiousness. Those with higher neuroticism scores exhibited smaller cortisol and cardiovascular stress reactions, whereas participants who were less agreeable and less open had smaller cortisol and cardiac reactions to stress. These associations remained statistically significant following adjustment for a range of potential confounding variables. Thus, a negative personality disposition would appear to be linked to diminished stress reactivity. These findings further support a growing body of evidence which suggests that blunted stress reactivity may be maladaptive.     

Personality pathways to mortality: Interleukin-6 links conscientiousness to mortality risk

Personality is associated consistently with mortality hazards, but the physiological pathways are not yet clear. Immune system dysregulation may be one such pathway due to its role in age-related morbidity and mortality. In this preregistered study, we tested whether interleukin-6 (IL-6) and C-reactive protein (CRP) mediated the associations between personality traits and mortality hazards. The sample included 957 participants (M ± SD = 58.65 ± 11.51 years; range = 35–86 years) from the Midlife in the United States Survey that had 14 years of follow-up. Higher conscientiousness was associated with lower mortality hazards, with each one standard deviation higher conscientiousness associated with a 35% lower mortality risk. IL-6, but not CRP, partially mediated this association, with IL-6 accounting for 18% of this association in the fully adjusted model. While there was initial evidence that the biomarkers mediated both neuroticism and agreeableness and mortality risk, the indirect effects were not significant when controlling for the sociodemographic variables. Taken together, higher conscientiousness may lead to a longer life partially as a result of lower IL-6. This work highlights the importance of biological pathways that link personality to future mortality risk.     

Electrophysiological evidence for early perceptual facilitation and efficient categorization of self‐related stimuli during an Implicit Association Test measuring neuroticism

The Implicit Association Test (IAT) is a widely used latency‐based categorization task that indirectly measures the strength of automatic associations between target and attribute concepts. So far, little is known about the perceptual and cognitive processes underlying personality IATs. Thus, the present study examined event‐related potential indices during the execution of an IAT measuring neuroticism (N = 70). The IAT effect was strongly modulated by the P1 component indicating early facilitation of relevant visual input and by a P3b‐like late positive component reflecting the efficacy of stimulus categorization. Both components covaried, and larger amplitudes led to faster responses. The results suggest a relationship between early perceptual and semantic processes operating at a more automatic, implicit level and later decision‐related categorization of self‐relevant stimuli contributing to the IAT effect.     

Anxious,introverted personality traits in patients with chronic subjective dizziness

Objectives

Chronic subjective dizziness (CSD) is a neurotologic disorder of persistent non-vertiginous dizziness, unsteadiness, and hypersensitivity to one's own motion or exposure to complex visual stimuli. CSD usually follows acute attacks of vertigo or dizziness and is thought to arise from patients' failure to re-establish normal locomotor control strategies after resolution of acute vestibular symptoms. Pre-existing anxiety or anxiety diathesis may be risk factors for CSD. This study tested the hypothesis that patients with CSD are more likely than individuals with other chronic neurotologic illnesses to possess anxious, introverted personality traits.

Methods

Data were abstracted retrospectively from medical records of 40 patients who underwent multidisciplinary neurotology evaluations for chronic dizziness. Twenty-four subjects had CSD. Sixteen had chronic medical conditions other than CSD plus co-existing anxiety disorders. Group differences in demographics, Dizziness Handicap Inventory (DHI) scores, Hospital Anxiety and Depression Scale (HADS) scores, DSM-IV diagnoses, personality traits measured with the NEO Personality Inventory — Revised (NEO-PI-R), and temperaments composed of NEO-PI-R facets were examined.

Results

There were no differences between groups in demographics, mean DHI or HADS-anxiety scores, or DSM-IV diagnoses. The CSD group had higher mean HADS-depression and NEO-PI-R trait anxiety, but lower NEO-PI-R extraversion, warmth, positive emotions, openness to feelings, and trust (all p < 0.05). CSD subjects were significantly more likely than comparison subjects to have a composite temperament of high trait anxiety plus low warmth or excitement seeking.

Conclusion

An anxious, introverted temperament is strongly associated with CSD and may be a risk factor for developing this syndrome.     

The prevalence of tinnitus and the relationship with neuroticism in a middle-aged UK population

Background

Previous research has suggested that a substantial proportion of the population are severely affected by tinnitus, however recent population data are lacking. Furthermore, there is growing evidence that the perception of severity is closely related to personality factors such as neuroticism.

Objective

In a subset (N = 172,621) of a large population sample of > 500,000 adults aged 40 to 69 years, (from the UK Biobank dataset) we calculated the prevalence of tinnitus and that which is perceived as bothersome, and examined the association between tinnitus and a putative predisposing personality factor, neuroticism.

Method

Participants were recruited through National Health Service registers and aimed to be inclusive and as representative of the UK population as possible. The assessment included subjective questions concerning hearing and tinnitus. Neuroticism was self-rated on 13 questions from the Eysenck Personality Inventory. Associations between neuroticism and tinnitus were tested with logistic regression analyses.

Results

Prevalence of tinnitus was significantly higher for males, and increased with age, doubling between the youngest and oldest age groups (males 13% and 26%; females 9% and 19% respectively). Of those with tinnitus, females were more likely to report bothersome tinnitus. Neuroticism was associated with current tinnitus and bothersome tinnitus, with the items: ‘loneliness’, ‘mood swings’, ‘worrier/anxious’ and ‘miserableness’, as the strongest associations of bothersome tinnitus.

Conclusions

Neuroticism was identified as a novel association with tinnitus. Individuals with tinnitus and higher levels of neuroticism are more likely to experience bothersome tinnitus, possibly as a reflection of greater sensitivity to intrusive experiences.