Assessing sickness behavior in the French: Validation of the French translation of the sickness questionnaire (SicknessQ) in a non-clinical French population.

The Sickness Questionnaire (SicknessQ) is a questionnaire developed to assess symptoms of sickness behavior, including somatic, behavioral, and affective dimensions. To promote cross-cultural assessments of sickness behavior, we aim to expand the use of this questionnaire to other populations and languages. The aim of the present study was to evaluate the French translation of SicknessQ in a French-speaking general population during the COVID-19 pandemic. One hundred and thirty-nine individuals completed the SicknessQ online, along with the construct criteria measures of self-rated health, state anxiety (STAI-S), and depressive symptoms (PHQ-9). The principal component analyses revealed two components: the first component included seven items concerning mood, motivation and experiences of fatigue and pain; the second component included three items concerning somatic sickness symptoms. Higher scores on the total scale and the two component subscales were associated with poorer self-rated health and higher STAI-S and PHQ-9 scores. Since the associations with construct criteria variables were relatively similar between the single- and the two-dimensional solutions, both the total scale and the subscales of the two components of the French SicknessQ can be used in future studies to measure sickness behavior in French-speaking populations.

Olfactory Cues of Naturally Occurring Systemic Inflammation: A Pilot Study of Seasonal Allergy.

INTRODUCTION: In an attempt to avoid contact with infectious individuals, humans likely respond to generalized rather than specific markers of disease. Humans may thus perceive a noninfectious individual as socially less attractive if they look (e.g., have facial discolouration), move (e.g., have a slower walking pace), or sound (e.g., sneeze) sick. This pilot study tested whether humans are averse to the body odour of noninfectious individuals with a low-grade systemic inflammation. METHODS: We collected the axillary body odour of individuals with severe seasonal allergy (N = 14) and healthy controls (N = 10) during and outside the allergy season and measured serum levels of two inflammatory cytokines (tumour necrosis factor-α and interleukin-5). Independent participants (N = 67) then sampled and rated these odours on intensity and pleasantness. RESULTS: While individuals with seasonal allergy had nominally more unpleasant and intense body odours during the allergy season, relative to outside the allergy season and to healthy controls, these effects were not significant. When examining immune markers, the change in perceived pleasantness of an individual's body odour (from out-to-inside pollen season) was significantly related to the change in their interleukin-5 levels but not to tumour necrosis factor-α. DISCUSSION: Our findings tentatively suggest that the human olfactory system could be sensitive to inflammation as present in a noncommunicable condition. Larger replications are required to determine the role of olfaction in the perception of infectious and noninfectious (e.g., chronic diseases) conditions.

Discriminating between sick and healthy faces based on early sickness cues: an exploratory analysis of sex differences.

Background and objectives: It has been argued that sex and disease-related traits should influence how observers respond to sensory sickness cues. In fact, there is evidence that humans can detect sensory cues related to infection in others, but lack of power from earlier studies prevents any firm conclusion regarding whether perception of sickness cues is associated with sex and disease-related personality traits. Here, we tested whether women (relative to men), individuals with poorer self-reported health, and who are more sensitive to disgust, vulnerable to disease, and concerned about their health, overestimate the presence of, and/or are better at detecting sickness cues. Methodology: In a large online study, 343 women and 340 men were instructed to identify the sick faces from a series of sick and healthy photographs of volunteers with an induced acute experimental inflammation. Participants also completed several disease-related questionnaires. Results: While both men and women could discriminate between sick and healthy individuals above chance level, exploratory analyses revealed that women outperformed men in accuracy and speed of discrimination. Furthermore, we demonstrated that higher disgust sensitivity to body odors is associated with a more liberal decision criterion for categorizing faces as sick. Conclusion: Our findings give strong support for the human ability to discriminate between sick and healthy individuals based on early facial cues of sickness and suggest that women are significantly, although only slightly, better at this task. If this finding is replicated, future studies should determine whether women's better performance is related to increased avoidance of sick individuals.

Human scent as a first-line defense against disease.

Individuals may have a different body odor, when they are sick compared to healthy. In the non-human animal literature, olfactory cues have been shown to predict avoidance of sick individuals. We tested whether the mere experimental activation of the innate immune system in healthy human individuals can make an individuals' body odor be perceived as more aversive (intense, unpleasant, and disgusting). Following an endotoxin injection (lipopolysaccharide; 0.6 ng/kg) that creates a transient systemic inflammation, individuals smelled more unpleasant compared to a placebo group (saline injection). Behavioral and chemical analyses of the body odor samples suggest that the volatile components of samples from "sick" individuals changed qualitatively rather than quantitatively. Our findings support the hypothesis that odor cues of inflammation in axillary sweat are detectable just a few hours after experimental activation of the innate immune system. As such, they may trigger behavioral avoidance, hence constituting a first line of defense against pathogens of infected conspecifics.

Internet-delivered cognitive behavioral therapy for adolescents with insomnia: Feasibility and preliminary efficacy.

BACKGROUND: Insomnia is common in adolescents. This study evaluated feasibility and preliminary efficacy of a six-week internet-delivered cognitive-behavioral therapy for insomnia (ICBT-I) in adolescents. METHODS: In this uncontrolled pilot study, participants (n = 27, 78% female) completed assessments pre- and post intervention. Data on recruitment, adherence to treatment, treatment activity, satisfaction and credibility was collected to assess feasibility. Self-reported insomnia symptoms, sleep parameters as well as depression, anxiety and daytime function were also assessed. RESULTS: Participants showed good adherence to treatment and found the intervention overall credible and satisfactory. From pre- to post-assessment, statistically significant improvements were found for insomnia symptoms (p < .001; d = 1.02), sleep onset latency (p < .001; d = .39), wake after sleep onset (p = .001; d = .34), sleep efficiency (p < .001; d = .5) and depression (p = .01, d = .37). Changes in scores of total sleep time, generalized anxiety, daytime sleepiness and functional disability were not significant. CONCLUSIONS: The present study indicates that ICBT-I is well accepted by adolescents, that insomnia symptoms and sleep parameters can improve following the intervention, and that co-morbid symptoms of depression can be reduced. Due to the limited sample size and the uncontrolled design, the suggested results need to be replicated in well-powered controlled clinical trials.

Mental health, stress, and well-being measured before (2019) and during (2020) COVID-19: a Swedish socioeconomic population-based study.

OBJECTIVES: Compare mental health, stress, and well-being in the Swedish population as measured before and during the COVID-19 pandemic. METHODS: Repeated cross-sectional design using data measured before (Jan-2019; n = 2791) and during (Oct/Nov-2020; n = 2926) COVID-19 pandemic in Swedish population-representative cohorts. Following constructs were measured: anxiety (Beck Anxiety Inventory), depression (Beck Depression Inventory-II), stress (Perceived Stress Scale-10 items), health-related quality of life (HRQOL[Functional Assessment of Cancer Therapy-General Population]) and self-rated health (SRH) was assessed with a single-item question. RESULTS: When adjusting for age, sex, education, and income there were significantly higher levels of anxiety (M̂ = 9.15 vs. 8.48, p < 0.01) and depression (M̂ = 3.64 vs. 3.30, p = 0.03), lower levels of stress (M̂ = 14.06 vs. 14.91, p < 0.001), but worsened HRQOL (M̂ = 76.40 vs. 77.92, p < 0.01) and SRH (M̂ = 6.91 vs. 7.20, p < 0.001), observed in 2020 compared to 2019. For the negative effects seen in anxiety, depression, HRQOL, and SRH, higher income and education had a protective effect. The decrease in stress was also correlated with higher income. CONCLUSIONS: The COVID-19 pandemic led to a small but significant worsening in mental health and well-being in the general Swedish population, where higher socioeconomic status seemed to have a protective effect.

Chronic fatigue syndromes: real illnesses that people can recover from.

The 'Oslo Chronic Fatigue Consortium' consists of researchers and clinicians who question the current narrative that chronic fatigue syndromes, including post-covid conditions, are incurable diseases. Instead, we propose an alternative view, based on research, which offers more hope to patients. Whilst we regard the symptoms of these conditions as real, we propose that they are more likely to reflect the brain's response to a range of biological, psychological, and social factors, rather than a specific disease process. Possible causes include persistent activation of the neurobiological stress response, accompanied by associated changes in immunological, hormonal, cognitive and behavioural domains. We further propose that the symptoms are more likely to persist if they are perceived as threatening, and all activities that are perceived to worsen them are avoided. We also question the idea that the best way to cope with the illness is by prolonged rest, social isolation, and sensory deprivation.Instead, we propose that recovery is often possible if patients are helped to adopt a less threatening understanding of their symptoms and are supported in a gradual return to normal activities. Finally, we call for a much more open and constructive dialogue about these conditions. This dialogue should include a wider range of views, including those of patients who have recovered from them.

Objective cognitive functioning in patients with stress-related disorders: a cross-sectional study using remote digital cognitive testing.

BACKGROUND: Patients with stress-related mental disorders often report cognitive impairment, but studies investigating objective cognitive impairment in patients with stress-related disorders have produced inconsistent findings. AIM: The primary aim of this study was to investigate objective cognitive functioning in patients diagnosed with the stress-related disorders adjustment disorder or exhaustion disorder, compared to a healthy normative group. Secondary aims were to conduct subgroup analyses of cognitive functioning between the diagnostic groups and explore associations between self-reported symptoms and cognitive functioning. METHODS: Cognitive test results on a digitally self-administered cognitive test battery from 266 patients (adjustment disorder, n = 131; exhaustion disorder, n = 135) were cross-sectionally compared with results from a healthy normative group (N = 184 to 692) using one-tailed t-tests. ANOVAs were conducted for subgroup analyses, and regression analyses for associations between self-reported symptoms and cognitive functioning. Effect sizes were calculated. RESULTS: Patients performed significantly worse than the normative group on all measures with small to moderate effect sizes ranging from d = -.13 to -.57. Those diagnosed with exhaustion disorder performed worse than norms on more measures than did patients with adjustment disorder, but no significant differences between diagnostic groups were found on any measure. Self-reported memory impairment was weakly associated with one of two memory measures. No clear associations between self-reported burnout symptoms and objective cognitive functioning were found. CONCLUSIONS: This study adds to the literature indicative of small to moderate objective cognitive impairments in patients diagnosed with stress-related mental disorders. Further exploration into mechanisms of cognitive functioning in different populations is needed for development of theoretical models that may explain the weak correlation between self-reported symptoms and objective measures. TRIAL REGISTRATION: ClinicalTrial.gov: NCT04797273. Trial registration date 15 March 2021. This study was also pre-registered on Open Science Framework (osf.io) with https://doi.org/10.17605/OSF.IO/TQXZV .

Humans can detect axillary odor cues of an acute respiratory infection in others.

Background and objectives: Body odor conveys information about health status to conspecifics and influences approach-avoidance behaviors in animals. Experiments that induce sickness in otherwise healthy individuals suggest that humans too can detect sensory cues to infection in others. Here, we investigated whether individuals could detect through smell a naturally occurring acute respiratory infection in others and whether sickness severity, measured via body temperature and sickness symptoms, was associated with the accuracy of detection. Methodology: Body odor samples were collected from 20 donors, once while healthy and once while sick with an acute respiratory infection. Using a double-blind, two-alternative forced-choice method, 80 raters were instructed to identify the sick body odor from paired sick and healthy samples (i.e. 20 pairs). Results: Sickness detection was significantly above chance, although the magnitude of the effect was low (56.7%). Raters' sex and disgust sensitivity were not associated with the accuracy of sickness detection. However, we find some indication that greater change in donor body temperature, but not sickness symptoms, between sick and healthy conditions improved sickness detection accuracy. Conclusion and implications: Our findings suggest that humans can detect individuals with an acute respiratory infection through smell, albeit only slightly better than chance. Humans, similar to other animals, are likely able to use sickness odor cues to guide adaptive behaviors that decrease the risk of contagion, such as social avoidance. Further studies should determine how well humans can detect specific infections through body odor, such as Covid-19, and how multisensory cues to infection are used simultaneously.

Lipopolysaccharide-induced changes in the kynurenine pathway and symptoms of sickness behavior in humans.

Metabolites of the kynurenine pathway are hypothesized to be implicated in inflammation-associated depression, but there is a lack of experimental studies in humans assessing the kinetics of kynurenine metabolites in relation to experimentally-induced sickness. The aim of the present study was to assess changes in the kynurenine pathway and to explore its relation to symptoms of sickness behavior during an acute experimental immune challenge. This double-blind placebo-controlled randomized cross-over study included 22 healthy human participants (n = 21 both sessions, Mage = 23.4, SD = 3.6, nine women) who received an intravenous injection of 2.0 ng/kg lipopolysaccharide (LPS) and saline (placebo) on two different occasions in a randomized order. Blood samples (0 h, 1 h, 1.5 h, 2 h, 3 h, 4 h, 5 h, 7 h post-injection) were analyzed for kynurenine metabolites and inflammatory cytokines. The intensity of symptoms of sickness behavior was assessed using the 10-item Sickness Questionnaire at 0 h, 1.5 h, 3 h, 5 h, and 7 h post-injection. LPS induced significantly lower concentrations of plasma tryptophan (at 2 h, 4 h, 5 h, and 7 h post-injection), kynurenine (at 2 h, 3 h, 4 h, and 5 h post-injection), nicotinamide (at 4 h, 5 h, and 7 h post-injection), and higher levels for quinolinic acid at 5 h post-injection as compared to placebo. LPS did not affect kynurenic acid, 3-hydroxykynurenine, and picolinic acid. The development of the sickness symptoms was largely similar across items, with the highest levels around 1.5-3 h post-injection. Changes in plasma levels of kynurenine metabolites seem to coincide rather than precede or follow changes in subjective sickness. Exploratory analyses indicate that higher Sickness Questionnaire total scores at 1.5-5 h post-injection were correlated with lower kynurenic acid and nicotinamide levels. These results lend further support for LPS-induced changes in the kynurenine pathway, but may not, as interpreted from blood levels, causally link to LPS-induced acute symptoms of sickness behavior. Future research may consider a larger sample to further scrutinize the role of the kynurenine pathway in the sickness response.

Inflammatory Blood Signature Related to Common Psychological Comorbidity in Chronic Pain.

Chronic pain is characterized by high psychological comorbidity, and diagnoses are symptom-based due to a lack of clear pathophysiological factors and valid biomarkers. We investigate if inflammatory blood biomarker signatures are associated with pain intensity and psychological comorbidity in a mixed chronic pain population. Eighty-one patients (72% women) with chronic pain (>6 months) were included. Patient reported outcomes were collected, and blood was analyzed with the Proseek Multiplex Olink Inflammation Panel (Bioscience Uppsala, Uppsala, Sweden), resulting in 77 inflammatory markers included for multivariate data analysis. Three subgroups of chronic pain patients were identified using an unsupervised principal component analysis. No difference between the subgroups was seen in pain intensity, but differences were seen in mental health and inflammatory profiles. Ten inflammatory proteins were significantly associated with anxiety and depression (using the Generalized Anxiety Disorder 7-item scale (GAD-7) and the Patient Health Questionnaire (PHQ-9): STAMBP, SIRT2, AXIN1, CASP-8, ADA, IL-7, CD40, CXCL1, CXCL5, and CD244. No markers were related to pain intensity. Fifteen proteins could differentiate between patients with moderate/high (GAD-7/PHQ-9 > 10) or mild/no (GAD-7/PHQ-9 < 10) psychological comorbidity. This study further contributes to the increasing knowledge of the importance of inflammation in chronic pain conditions and indicates that specific inflammatory proteins may be related to psychological comorbidity.

Disgusting odors trigger the oral immune system.

Recent research has characterized the behavioral defense against disease. In particular the detection of sickness cues, the adaptive reactions (e.g. avoidance) to these cues and the mediating role of disgust have been the focus. A presumably important but less investigated part of a behavioral defense is the immune system response of the observer of sickness cues. Odors are intimately connected to disease and disgust, and research has shown how olfaction conveys sickness cues in both animals and humans. This study aims to test whether odorous sickness cues (i.e. disgusting odors) can trigger a preparatory immune response in humans. We show that subjective and objective disgust measures, as well as TNFα levels in saliva increased immediately after exposure to disgusting odors in a sample of 36 individuals. Altogether, these results suggest a collaboration between behavioral mechanisms of pathogen avoidance in olfaction, mediated by the emotion of disgust, and mechanisms of pathogen elimination facilitated by inflammatory mediators. Disgusting stimuli are associated with an increased risk of infection. We here test whether disgusting odors, can trigger an immune response in the oral cavity. The results indicate an increase level of TNFα in the saliva. This supports that disease cues can trigger a preparatory response in the oral cavity.

Characterization of exhaustion disorder and identification of outcomes that matter to patients: Qualitative content analysis of a Swedish national online survey.

Fatigue is a common presenting problem in healthcare settings, often attributed to chronic psychosocial stress. Understanding of fatigue and development of evidence-based treatments is hampered by a lack of consensus regarding diagnostic definitions and outcomes to be measured in clinical trials. This study aimed to map outcome domains of importance to the Swedish diagnosis stress-induced exhaustion disorder (ED; ICD-10, code F43.8 A). An online survey was distributed nationwide in Sweden to individuals who reported to have been diagnosed with ED and to healthcare professionals working with ED patients. To identify outcome domains, participants replied anonymously to four open-ended questions about symptoms and expectations for ED-treatment. Qualitative content analysis was conducted of a randomized subsample of respondents, using a mathematical model to determine data saturation. Six hundred seventy participants (573 with reported ED, 97 healthcare professionals) completed the survey. Qualitative content analysis of answers supplied by 105 randomized participants identified 87 outcomes of importance to ED encompassing physical, cognitive, and emotional symptoms as well as functional disability. Self-rating scales indicated that many ED participants, beyond reporting fatigue, also reported symptoms of moderate to severe depression, anxiety, insomnia, poor self-rated health, and sickness behavior. This study presents a map of outcome domains of importance for ED. Results shed light on the panorama of issues that individuals with ED deal with and can be used as a step to further understand the condition and to reach consensus regarding outcome domains to measure in clinical trials of chronic stress and fatigue. Preregistration: Open Science Framework (osf.io) with DOI https://doi.org/10.17605/OSF.IO/4VUAG.

Work ability and psychological distress in a working population: results from the Stockholm Public Health Cohort.

AIMS: Psychological distress is a global public health concern with individual and societal implications causing work-related disability and loss of productivity. It is less known how much work ability contributes to the development of psychological distress. This study aimed to assess the association between self-perceived physical and mental work ability in relation to job demands, and the incidence of psychological distress in a Swedish working population. METHODS: Data were obtained from three subsamples of the Stockholm Public Health Cohort with baseline in 2010 and follow-up in 2014, based on a working population in Stockholm County aged 18-60 years, with no or mild psychological distress at baseline (n=29,882). Self-perceived physical and mental work ability in relation to job demands were assessed at baseline with a subscale from the Work Ability Index. Study participants scoring 4 or more on the General Health Questionnaire 12 at follow-up were classified as having developed psychological distress during the study period. Poisson log linear regression was used to calculate crude and adjusted rate ratios with 95% confidence intervals. RESULTS: At follow-up, 2543 participants (12%) had developed psychological distress. Reporting poor physical and/or poor mental work ability in relation to job demands at baseline was associated with an almost doubled rate ratio of psychological distress at follow-up, compared to reporting good work ability (rate ratio 1.8; 95% confidence interval 1.6-2.0). CONCLUSIONS: Poor work ability is associated with a higher incidence of future psychological distress compared to good work ability.

Disturbed sleep and patterns of psychiatric symptoms and function in a school-based sample of adolescents.

BACKGROUND: Sleep problems are common in adolescence and often related to psychopathology and impaired functioning. However, most studies have used summative scores, and little is known about how adolescents with disrupted sleep perceive their specific symptoms and dysfunctions. This study explored differences in levels of psychiatric symptoms and functional ability between Swedish adolescents with and without self-reported disturbed sleep in a school-based sample. METHODS: Swedish adolescents (n = 618, mean age 15.7+/-1.9yrs) answered the PROMIS pediatric measures for fatigue, anxiety, depression, pain interference, anger, physical activity and peer and family relationships. Logistic regression analyses were performed to assess differences between respondents with and without disturbed sleep. RESULTS: Disturbed sleep was associated with higher levels of symptoms of fatigue, anxiety, depression, anger and pain interference, as well as lower functional abilities in terms of physical activity and peer- and family relationships. Adolescents reporting disturbed sleep generally displayed a pattern of impaired executive functioning, internal emotional distress and school- and sleep related worry and dysfunction, as compared to physical disability, aggressive behavior, stress and generalized worry. CONCLUSIONS: The present study adds to the understanding of how disturbed sleep and specific psychiatric symptoms and functional ability are interrelated, which may also have clinical implications.

Exhaustion disorder: scoping review of research on a recently introduced stress-related diagnosis.

BACKGROUND: Symptoms related to chronic stress are prevalent and entail high societal costs, yet there is a lack of international consensus regarding diagnostics and treatment. A new stress-related diagnosis, exhaustion disorder, was introduced into the Swedish version of ICD-10 in 2005. Since then, use of the diagnosis has increased rapidly. AIMS: To create the first comprehensive synthesis of research on exhaustion disorder to report on the current state of knowledge. Preregistration: Open Science Framework (http://www.w3.org/1999/xlink">osf.io), doi 10.17605/OSF.IO/VFDKW. METHOD: A PRISMA-guided scoping review of all empirical studies of exhaustion disorder was conducted. Searches were run in the MEDLINE, PsycInfo and Web of Science databases. Data were systematically charted and thematically categorised based on primary area of investigation. RESULTS: Eighty-nine included studies were sorted into six themes relating to lived experience of exhaustion disorder (n = 9), symptom presentation and course (n = 13), cognitive functioning (n = 10), biological measures (n = 24), symptom measurement scales (n = 4) and treatment (n = 29). Several studies indicated that individuals with exhaustion disorder experience a range of psychiatric and somatic symptoms beyond fatigue, but robust findings within most thematic categories were scarce. The limited number of studies, lack of replication of findings and methodological limitations (e.g. small samples and scarcity of specified primary outcomes) preclude firm conclusions about the diagnostic construct. CONCLUSIONS: More research is needed to build a solid knowledge base for exhaustion disorder. International collaboration regarding the conceptualisation of chronic stress and fatigue is warranted to accelerate the growth of evidence.