Personality and fatigue: meta-analysis of seven prospective studies

Five-factor personality traits and functional somatic disorder: A systematic review and meta-analysis

INTRODUCTION

Functional Somatic Disorders (FSD) is an umbrella term for various conditions characterized by persistent and troublesome physical symptoms, that are not better explained by other psychiatric or somatic conditions. Personality traits may play a crucial role in FSD, but the link is not fully understood. This study presents a systematic review and meta-analysis examines the relationship between the Five-Factor Model (FFM) of personality traits and FSD.

METHODS

The review was based on the PRISMA statement, and drew data from systematic searches in PsycInfo, PubMed, and Embase. To be eligible for inclusion, studies had to include eligible FSD groups and control groups and to assess FFM traits. Data were analyzed using random effects models. Sub-group and sensitivity analyses as well as meta-regression were used to explore the heterogeneity and robustness of findings.

RESULTS

In total 6841 records were screened and 52 included. FSD cases scored higher on neuroticism (k = 46, Hedge's g = 0.72, [95 % CI, 0.61: 0.83]) and lower on extraversion (k = 31, g = -0.41, [-0.55:-0.28]) and agreeableness (k = 15, g = -0.22, [-0.36:-0.09]) than healthy/unspecified controls. FSD cases scored higher on neuroticism (k = 9, g = 0.26 [0.08:0.44]) and agreeableness (k = 4, g = 0.43 [0.28:0.59]) than somatic controls, but did not differ on extraversion (k = 6, g = -0.17 [-0.45:0.11]). No significant differences were found for conscientiousness and openness. For psychiatric controls, meta-analysis was only possible for neuroticism (k = 3,= -0.61, [-1.98:0.77]). Findings displayed significant heterogeneity but no publication bias.

CONCLUSIONS

This review reveals significant associations between FFM traits and FSD, providing insight into the etiology, classification, and management of FSD.

Self-perceptual blindness to mental fatigue in mining workers

Mental fatigue is a psychophysiological state that adversely impacts performance in cognitive tasks, increasing risk of occupational hazards. Given its manifestation as a conscious sensation, it is often measured through subjective self-report. However, subjective measures are not always true measurements of objective fatigue. In this study, we investigated the relationship between objective and subjective fatigue measurements with the preventive AccessPoint fatigue assay in Chilean mine workers. Subjective fatigue was measured through the Samn-Perelli scale, objective fatigue through a neurocognitive reaction time task. We found that objective and subjective fatigue do not correlate (-0.03 correlation coefficient, p < 0.001). Moreover, severe fatigue cases often displayed absence of subjective fatigue coupled with worse cognitive performance, a phenomenon we denominated Perceptual Blindness to fatigue. These findings highlight the need for objective fatigue measurements, particularly in high-risk occupational settings such as mining. Our results open new avenues for researching mechanisms underlying fatigue perception and its implications for occupational health and safety.

Association between personality traits and concerns about falling among older patients: the mediating role of subjective age

Background

Older patients are at high risk of falling, and regular assessments of their concerns about falling (CaF) are often recommended. The present study aimed to investigate the association between CaF and personality traits among older patients as well as to elucidate the mediating role of subjective age.

Method

A cross-sectional study was conducted among 407 patients aged over 60 years in a tertiary hospital located in Chengdu, Sichuan Province, from March 2023 to May 2023. Predesigned electronic questionnaires were distributed to collect relevant data. Four different models (both crude and adjusted weighted linear regression models) were constructed based on the confounders. Confounders were gradually put into the models to control for bias and to examine the stability of the correlations. Bootstrap sampling was employed to examine the mediating role of subjective age.

Result

According to the fully adjusted model, neuroticism (β = 0.17, 95% CI: 0.02 to 0.31, p for trend = 0.02), extraversion (β = -0.07, 95% CI: -0.15 to 0.001, p for trend = 0.05), and subjective age (β = 2.02, 95% CI: 1.28 to 2.78, p for trend <0.001) were consistently correlated with CaF. Mediating analysis revealed that extraversion was negatively related with CaF both directly and indirectly, via subjective age [23.2% partial effect, bootstrap 95%CI: -0.024(-0.080, -0.000)]. Higher neuroticism was consistently related to older subjective age (β = 0.002, 95% CI: 0.001 to 0.004, p for trend = 0.006), while higher levels of conscientiousness, openness, and extraversion were consistently correlated with younger subjective age(β = -0.002, p for trend = 0.04; β = -0.003, p for trend = 0.003; β = -0.002, p for trend = 0.0, respectively).

Conclusion

Extraversion and neuroticism were significantly correlated with CaF. Moreover, subjective age partially mediated the relationship between extraversion and CaF. Furthermore, subjective age was found to be associated with both CaF and personality traits. These findings highlighted the important roles of personality traits and subjective age in assessments of CaF and in the development of strategies for preventing falls among older patients.

Personality and Pain Outcomes in Rheumatic Disease: The Mediating Role of Psychological Flexibility

BACKGROUND

Chronic pain is associated with increased disability and vulnerability to emotional disorders. Personality and psychological flexibility (PF) describe interindividual differences that shape the adjustment to chronic pain. Specifically, PF was found to be associated with pain, fatigue, anxiety, and depression intensity. Although previous studies established strong correlations between personality and pain outcomes, evidence on the nature of this relationship is scarce. Therefore, the objective of this study is to explore the mediating effect of PF on the relationship between personality and distress.

METHODS

This transversal study included 108 participants (age M = 56.7, SD = 11.3) diagnosed with musculoskeletal chronic pain. Self-reported measures were administered by the medical care team. Multiple mediation models were performed for estimating the indirect effects on each outcome variable.

RESULTS

After controlling for age and gender covariates, we found that PF completely mediated the relationship between personality traits and all pain outcomes and partially mediated the impact of extraversion on anxiety. In addition, emotional stability also had an indirect effect on anxiety through PF.

CONCLUSIONS

Personality traits and PF are significant predictors of pain outcomes. PF represents a core process mediating the impact of personality traits on the perceived intensity of pain, fatigue, anxiety, and depression in patients with rheumatic disease. These results could facilitate the application of individualized psychological interventions in clinical contexts targeting the reduction of emotional avoidance and in chronic pain patients.

Personality traits and polypharmacy: meta-analysis of five samples

OBJECTIVE

The present study examined the prospective relationship between personality traits and the risk of polypharmacy.

METHODS AND MEASURES

Participants (age range: 16-101 years; N > 15,000) were from the English Longitudinal Study of Ageing (ELSA), the Midlife in the United States Study (MIDUS), the Health and Retirement Study (HRS), the Wisconsin Longitudinal Study of Aging (WLS), and the Longitudinal Internet Studies for the Social Sciences (LISS). In each sample, personality traits and demographic factors were assessed at baseline. Number of medications was obtained from 2 to 20 years later.

RESULTS

Random-effect meta-analyses revealed that higher neuroticism was related to a higher risk of polypharmacy (Odd Ratio = 1.30; 95% CI 1.17-1.46) and excessive polypharmacy (Odd Ratio = 1.44; 95% CI 1.18-1.77) whereas higher conscientiousness (Odd Ratio = 0.84; 95% CI 0.74-0.95) and extraversion (Odd Ratio = 0.85; 95% CI 0.73-0.98) were associated with a lower risk of polypharmacy. Openness and agreeableness were unrelated to polypharmacy. Body mass index, number of chronic conditions, and depressive symptoms partially mediated the association between personality and the number of medications.

CONCLUSION

The present study provides replicable and robust evidence that neuroticism is a risk factor for simultaneous use of multiple medications, whereas conscientiousness and extraversion may play a protective role.

[Chronic fatigue: What investigations? And what for?]

Chronic fatigue is a frequent complaint, expressed at all levels of the healthcare system. It is perceived as disabling in a high proportion of cases, and internists are frequently called upon to find "the" cause. The etiological diagnostic approach of an unexplained state of fatigue relies on the careful search for more specific clues by questioning and clinical examination. It is necessary to recognize the limited place of complementary examinations apart from the basic biological parameters. Simple rating scales can be useful in the etiological and differential diagnosis of fatigue. Chronic fatigue syndrome (CFS), in the current state of knowledge, cannot be considered as a specific pathological entity distinct from idiopathic chronic fatigue states, and does not have validated biomarkers. It is important to know that a state of chronic asthenia often results from several intricated etiological factors (biological, psychological and social), to be classified as predisposing, precipitating and perpetuating. The metabolic and cardiorespiratory exercise test has a major place in the assessment and management of fatigue, as a prerequisite for personalized retraining or adapted physical activity (APA), which are the treatments of choice for chronic fatigue.

Personality Traits and Fatigue in Multiple Sclerosis: A Narrative Review

(1) Background: Multiple sclerosis (MS) is a chronic neurodegenerative autoimmune disease. Fatigue is a prevalent and debilitating symptom that significantly impacts the quality of life of these patients. A relationship between personality traits and fatigue in MS has been hypothesized but not clearly defined. (2) Methods: A literature search was carried out from databases up to April 2023 for studies correlating personality traits and fatigue in patients suffering from MS. (3) Results: A total of ten articles was included; most of the studies depict a neuroticism-fatigue correlation; however, they were not consistent in terms of the fatigue, personality, and covariate assessments. (4) Conclusions: The clinical and methodological heterogeneity of the included studies prevented us from drawing any firm conclusion on the link between personality traits and fatigue in MS. Several models of personality and different fatigue assessments have been found. Despite this, a common pathway shows that the neuroticism trait or similar personality patterns has a role in fatigue diagnosis. This may be a useful target to improve the quality of life and enhance the modification of the disease treatment results. Further homogeneous and longitudinal studies are needed.

Personality and aging-related immune phenotype

An aging-related immune phenotype (ARIP) has been defined as a decrease in naïve T cells (T_N) relative to the accumulation of memory T cells (T_M). Recent research implicates ARIP measures, such as CD4 +T_N/T_M and CD8 +T_N/T_M ratios, in multimorbidity and mortality. This study examined whether psychological dispositions that assess how people think, feel, and behave are related to CD4 +T_N/T_M and CD8 +T_N/T_M. Participants were adults aged 50-104 years (N = 4798; 58% women, Mean Age= 67.95, SD= 9.56) from the Health and Retirement Study. Data on CD4 +T_N/T_M and CD8 +T_N/T_M were obtained in 2016. Data on personality, demographic factors, and potential clinical (body mass index, disease burden), behavioral (smoking, alcohol, physical activity), psychological (depressive symptoms, stress), and biological (cytomegalovirus IgG antibodies) mediating factors were obtained in 2014/2016. Controlling for demographic factors, higher conscientiousness was related to higher CD4 +T_N/T_M and CD8 +T_N/T_M. To a lesser extent, higher neuroticism and lower extraversion were associated with lower CD4 +T_N/T_M. Physical activity, and to a lesser extent BMI and disease burden, were the most robust mediators between personality and ARIP measures. Cytomegalovirus IgG level mediated the association between conscientiousness and both CD4 +T_N/T_M and CD8 +T_N/T_M. This study provides novel evidence that personality is related to ARIP. Higher conscientiousness and, to a lesser extent, higher extraversion may be protective against age-related immunophenotype change, whereas neuroticism may be a risk factor.

Personality associations with lung function and dyspnea: Evidence from six studies

OBJECTIVE

The present study examined the association between Five Factor Model personality traits and lung function and dyspnea.

METHODS

Participants were middle aged and older adults aged 34-103 years old (N > 25,000) from the Midlife in the United States Study (MIDUS), the Health and Retirement Study (HRS), the English Longitudinal Study of Ageing (ELSA), the National Health and Aging Trends Survey (NHATS), and the Wisconsin Longitudinal Study graduate (WLSG) and sibling (WLSS) samples. Data on peak expiratory flow (PEF), dyspnea, personality traits, smoking, physical activity, body mass index (BMI), emotional/psychiatric problems, and demographic factors were obtained in each sample.

RESULTS

A meta-analysis indicated that higher neuroticism was related to lower PEF, higher risk of PEF less than 80% of predicted value, and higher risk of dyspnea. In contrast, higher extraversion and conscientiousness were associated with higher PEF, lower likelihood of PEF lower than 80% of the predicted value, and lower risk of dyspnea. Higher openness was related to higher PEF and lower risk of PEF less than 80%, whereas agreeableness was related to higher PEF and lower risk of dyspnea. Smoking, physical activity, BMI and emotional/psychiatric problems partially accounted for these associations. There was little evidence that lung disease moderated the association between personality and PEF and dyspnea.

CONCLUSIONS

Across cohorts, this study found replicable evidence that personality is associated with lung function and associated symptomatology.

Fatigue and Secondary Media Impacts in the Automated Vehicle: A Multidimensional State Perspective

Safety researchers increasingly recognize the impacts of task-induced fatigue on vehicle driving behavior. The current study (N = 180) explored the use of a multidimensional fatigue measure, the Driver Fatigue Questionnaire (DFQ), to test the impacts of vehicle automation, secondary media use, and driver personality on fatigue states and performance in a driving simulator. Secondary media included a trivia game and a cellphone conversation. Simulated driving induced large-magnitude fatigue states in participants, including tiredness, confusion, coping through self-comforting, and muscular symptoms. Consistent with previous laboratory and field studies, dispositional fatigue proneness predicted increases in state fatigue during the drive, especially tiredness, irrespective of automation level and secondary media. Similar to previous studies, automation slowed braking response to the emergency event following takeover but did not affect fatigue. Secondary media use relieved subjective fatigue and improved lateral control but did not affect emergency braking. Confusion was, surprisingly, associated with faster braking, and tiredness was associated with impaired control of lateral position of the vehicle. These associations were not moderated by the experimental factors. Overall, data support the use of multidimensional assessments of both fatigue symptoms and information-processing components for evaluating safety impacts of interventions for fatigue.

Is the Pandemic Wearing Us Out? A Cross-Sectional Study of the Prevalence of Fatigue in Adult Twins without Previous SARS-CoV-2 Infection

During the pandemic, mental health was not only impaired in people after a SARS-CoV-2 infection, but also in people without previous infection. This is the first study on twins without prior SARS-CoV-2 infection to estimate the influence of genetic components and shared as well as individual environments on pandemic-associated fatigue. The study sample included 55 monozygotic and 45 dizygotic twin pairs. A total of 34.5% reported an increase in fatigue since the pandemic. A significant correlation was shown between the responses within monozygotic (χ2[1] = 11.14, p = 0.001) and dizygotic pairs (χ2[1] = 18.72, p < 0.001). In all pandemic-associated fatigue dimensions, individual environment (ranging from e2 = 0.64 to e2 = 0.84) and heritability (ranging from h2 = 0.32 to h2 = 1.04) seem to have the highest impact. The number of comorbidities significantly correlated with physical fatigue (Spearman’s ρ = 0.232, p < 0.001) and psychological impairment due to pandemic measures with the total fatigue score (Spearman’s ρ = 0.243, p < 0.001). However, calculated ANCOVAs with these significant correlations as covariates showed no significant influence on the mean values of the respective fatigue dimensions. Susceptibility to pandemic-associated fatigue may be genetically and environmentally determined, while intensity is also influenced by individual components. The prevalence of fatigue is high even in individuals without prior SARS-CoV-2 infection. Future mental health prevention and intervention programs should be implemented to alleviate the impact of the pandemic on the global population.