Search

Comorbidity with various health conditions is common in environmental intolerances (EIs), which restricts understanding for what symptoms that are associated with the intolerance per se. The present objectives were to study (i) prevalence of a broad range of specific symptoms in chemical, building-related, electromagnetic field-(EMF) related, and sound EI, irrespective of comorbidity, (ii) prevalence of symptoms in body systems in exclusive EIs, and (iii) increased risk of symptoms in body systems in exclusive EIs that cannot be referred to functional somatic syndromes, inflammatory diseases or mental disorders. Cross-sectional data (n = 4941) were used from two combined population-based surveys, the Va center dot sterbotten (Sweden) and center dot Osterbotten (Finland) Environmental Health Studies. Categorization of EI cases and controls were based on self-reports. Symptoms were assessed with the Environmental Hypersensitivity Symptom Inventory, and these were converted to 27 symptoms of the International Classification of Primary Care, 2nd edition, in eight chapters of body systems. The results showed, with few exceptions, that all assessed specific symptoms were significantly more prevalent in all four EIs than in referents. Although a large overlap between EIs, characteristic body system symptoms were eye and respiratory symptoms in chemical and building-related intolerance, skin symptoms in EMF-related intoler-ance, and general and unspecified, digestive, eye, cardiovascular, neurological, and psychological symptoms in sound intolerance. After controlling for various comorbidities, all studied body system symptoms were positively associated with chemical intolerance, fewer with sound intolerance, only one with building-related intolerance, and none with EMF-related EI. In conclusion, a broad range of symptoms are reported in all four EIs implying common mechanisms, but symptoms of certain body systems are more likely to be reported in a certain EI that cannot be explained by comorbidity.

Background Self-rated subjective cognitive decline (SCD) and subjective olfactory impairment (SOI) are associated with objective cognitive decline and dementia. However, their relationship and co-occurrence is unknown. We aimed to (a) describe the occurrence of SOI, SCD and their overlap in the general population; (b) compare SOI and SCD in terms of longitudinal associations with corresponding objective olfactory and cognitive measures; and (c) describe how SOI and SCD may lead to distinct sensory and cognitive outcomes. Methods Cognitively unimpaired individuals from the third wave of the Swedish population-based Betula study (n = 784, aged 35–90 years; 51% females) were split into self-rated SOI, SCD, overlapping SCD + SOI, and controls. Between-subject and within-subject repeated-measures MANCOVA were used to compare the groups regarding odor identification, cognition, age, sex, and education. Spearman correlation was used to assess the different patterns of association between olfaction and cognition across groups. Results SOI was present in 21.1%, whereas SCD was present in 9.9% of participants. According to a chi-square analysis, the SCD + SOI overlap (2.7%) is on a level that could be expected if the phenomena were independent. Odor identification in SOI showed decline at the 10-year follow-up (n = 284) and was positively associated with cognition. The SOI and SCD groups showed distinct cognitive-olfactory profiles at follow-up. Conclusions SOI occur independently of SCD in the population, and these risk factors are associated with different cognitive and olfactory outcomes. The biological causes underlying SOI and SCD, as well as the risk for future cognitive impairment, need further investigation.

Objective: Burnout results in individual suffering and high societal costs, and is associated with somatic symptoms, anxiety and depression, calling for prevention by early identification. The objectives were to (i) determine prevalence of specific somatic symptoms in burnout, (ii) identify the symptoms, referred to as somatic symptoms of burnout (SS-B), that are particularly associated with burnout, (iii) determine their extent of association with burnout, and (iv) determine how well a certain number of SS-B differentiates participants with and without burnout in a general Swedish adult population. Methods: Cross-sectional, population-based data were used from 687 participants high on burnout, and 2544 referents based on the Shirom-Melamed Burnout Questionnaire. The Patient Health Questionnaire 15-item Somatic Symptom Severity Scale was used to assess common somatization symptoms, and the Hospital Anxiety and Depression Scale to assess anxiety and depression. Results: Feeling tired/having low energy, back pain, joint/limb pain, trouble sleeping, headaches, stomach pain, nausea/gas/indigestion, and constipation/loose bowels/diarrhea were most prevalent in burnout (57.2–95.0%). These symptoms, except for joint/limb pain, and dizziness, were also identified as the SS-B, with odds ratios of 2.34–12.74 and 1.95–9.11 when adjusted for background variables, and for anxiety and depression, respectively. Corresponding odds ratios for each additional number of SS-B were 1.69 and 1.52, respectively. The highest balanced accuracy (71.6%) for predicting burnout was found for ≥4 SS-B. Conclusion: Fatigue, pain and gastrointestinal symptoms are particularly common in burnout. Further studies may show whether clinicians should consider screening for burnout when patients present with SS-B without pathophysiological explanations.

Insomnia and burnout are highly prevalent in the general population, calling for understanding of its causes. Taking a broad approach, the aim of this study was to determine various mental and somatic risk factors for development of insomnia and burnout and stratifying for sex and age group. Questionnaire data were used from a Swedish population-based sample aged 18–79 years, from which cohorts without insomnia (n = 1702) and without burnout (n = 1972) at baseline were followed-up after 3 years. Self-reports of eight mental and somatic conditions at baseline were used as independent variables in logistic regression analyses to predict development of insomnia and burnout at 3-year follow-up. All eight studied conditions were significant risk factors for development of both insomnia (odds ratio, OR = 1.62–2.73) and burnout (OR = 2.20–3.21). Burnout and poor self-rated health had the highest ORs for insomnia, and poor self-rated health, anxiety and somatic symptoms had the highest ORs for burnout. The ORs were generally similar between men and women, whereas age groups tended to differ in some of the risk factors. The study highlights the importance of a broad assessment of both mental and somatic conditions in the prevention of insomnia and burnout.

Background Non-adherence to preventive guidelines on cardiovascular disease calls for an interdisciplinary approach acknowledging psychological factors of relevance for risk communication and lifestyle modification. Evidence is building up regarding the advantage of sharing arterial imaging evidence of subclinical atherosclerosis with asymptomatic individuals, but there is limited understanding of how this relates to mechanisms of importance for behavioural change. Longitudinal studies on associations between patients’ reactions and lifestyle modification are missing. The population-based randomized controlled trial VIPVIZA investigates the impact of pictorial information about subclinical atherosclerosis, added to traditional risk factor-based communication. The intervention includes a personalized, colour-coded and age-related risk communication strategy and a motivational conversation, and has been shown to reduce cardiovascular disease risk. In the present study we assessed cognitive and emotional reactions to the intervention, and how these reactions are associated to lifestyle modification. Methods The participants’ evaluation of the risk communication was assessed in the intervention group (n = 1749). Lifestyle modification was assessed with a lifestyle index based on physical activity, diet, smoking and alcohol consumption at baseline and after 3 years. Associations between cognitive and emotional response and lifestyle modification were tested with analyses of covariance in a subset of participants (n = 714–857). Results The intervention increased understanding of personal CVD risk, the possibility to influence the risk, and how to influence the risk. Severity of atherosclerosis was associated with emotional reactions, but emotions of strong negative valance were uncommon. Cognitive response and emotional arousal evoked by the intervention were positively associated with lifestyle modification, whereas negative emotions in isolation were not. High level of cognitive response in combination with high level of emotional arousal was found to be most beneficial for lifestyle modification. Conclusions The results demonstrate the potential of communicating asymptomatic atherosclerosis with a pictorial, colour-coded and age-related strategy, also including a motivational conversation. Furthermore, the results show the importance of CVD risk communication evoking engagement, and that an interaction between cognitive and emotional reactions might be central for sustained lifestyle modification. Our results also indicate that, in an asymptomatic population, atherosclerosis screening may strengthen disease prevention and health promotion. Trial registration: ClinicalTrials.gov identifier: NCT01849575. Registration date 08/05/2013.

The overall aim of the present study was to examine the construct validity of different versions of the Shirom-Melamed Burnout Questionnaire/Measure (SMBQ/M) suggested in previous work, as well as to provide normative data for a large population-based sample in Sweden with a broad range in age. Cross-sectional data from the Västerbotten Environmental Health Study in Sweden were used. The 3406 participants (56% women) in this study, aged 18–79 years, constituted a random sample stratified for age and sex. Participants responded to a questionnaire including the 4-factor 22-item version of the SMBM as well as background questions and a number of validated questionnaire instruments assessing for example, sleep disturbance, depression, anxiety, perceived stress, and somatic symptoms. The dimensionality of different versions of the SMBM were examined with confirmatory factor analysis. A modified 4-factor 19-item model of the SMBM provided good model-fit, and two 2-factor models (11-item and 6-item) provided excellent model fit. The relationships to relevant psychological constructs provided support for convergent validity for the suggested versions of the SMBM. Finally, normative data were obtained for a broad age group for the different versions. In conclusion, we suggest that for assessing the core of the burnout construct in terms of emotional and physical exhaustion and cognitive weariness, the SMBM-11 or SMBM-6 for repeated measures, are to be used. For a broader assessment of burnout incorporating both symptoms and information about the process of exhaustion via the subscales of listlessness and tension, we recommend the use of the modified 4-factor SMBM-19.

Helplessness and hopelessness are transdiagnostic and aggravating factors of mental ill health, but their relation with somatization is not well documented. The main objectives were to identify somatic symptoms that are particularly associated with helplessness, referred to as somatic symptoms of helplessness (SS-He), and hopelessness, referred to as somatic symptoms of hopelessness (SS-Ho), determine increased risk of helplessness and hopelessness if having these symptoms and a certain number of these symptoms, and determine sensitivity and specificity in identifying helplessness and hopelessness based on number of these symptoms in a general Swedish sample. Population-based data from validated questionnaire instruments were used from 3,210 participants who constituted case groups of helplessness and hopelessness, and corresponding reference groups. Among 15 common somatic symptoms, five SS-He (e.g., feeling tired/having low energy) and five SS-Ho (e.g., dizziness) were identified, showing increased risk of helplessness and hopelessness that ranged from the factor 1.73 to 2.58 and from 1.44 to 1.92, respectively, which decreased considerably when controlled for depression and anxiety. The risk of helplessness increased by the factor 1.49 for each additional SS-He, and by 1.38 for each SS-Ho. A cutoff of two/three or more SS-He showed a sensitivity of 81.7/63.7% and a specificity of 40.6/61.4% in identifying helplessness, and 77.4/54.6% and 40.4/66.1%, respectively, in identifying hopelessness based on two/three or more SS-Ho. Primary care clinicians may consider further investigation of helplessness and hopelessness as well as depression and anxiety if presenting with these symptoms.

Submicroscopic nanoparticles (NPs) in air have received much attention due to their possible effects on health and wellbeing. Adverse health impacts of air pollution may not only be associated with level of exposure, but also mediated by the perception of the pollution and by beliefs of the exposure being hazardous. The aim of this study was to test a model that describes interrelations between NP pollution, perceived air quality, health risk perception, stress, and sick building syndrome. In the NanoOffice study, the level of NPs was measured and a survey on health risk perception was conducted among 260 employees in twelve office buildings in northern Sweden. Path analyses were performed to test the validity of the model. The data refute the model proposing that the NP exposure level significantly influences stress, chronic diseases, or SBS symptoms. Instead, the perceived exposure influences the perceived risk of NP, and the effect of perceived exposure on SBS and chronic disease is mediated by stress. There was little concern about nanoparticles, despite relatively high levels in some facilities. Perceived pollution and health risk perception may explain a large part of the environmentally induced symptoms and diseases, particularly in relatively low levels of pollution. The research results raise important questions on the physiologically or psychologically mediated health effects of air pollution.

Parosmia, distorted smell sensations, is a common consequence of respiratory virus infections. The phenomenon is not well understood in terms of its impact and long-term outcomes. We examined self-reported experiences of parosmia in a population-based sample from the Betula study that was conducted in Umeå in northern Sweden (baseline data collected in 1998–2000). We used a baseline sample of 2168 individuals aged 35–90 years and with no cognitive impairment at baseline. We investigated the prevalence of parosmia experiences and, using regression analyses, its relationship to other olfactory and cognitive variables and quality of life. Benefitting from the longitudinal study design, we also assessed the persistence of parosmia over 5 and 10 years prospectively. Parosmia experiences were prevalent in 4.8% of the population and it often co-occurred with phantosmia (“olfactory hallucinations”), but was not associated with lower self-rated overall quality of life or poor performance on olfactory or cognitive tests. For some individuals, parosmia was retained 5 years (17.0%) or even 10 years later (10.3%). Thus, parosmia experiences are commonly reported in the population, and can be persistent for some individuals, but might be mostly benign in nature. Our work complements research on clinical-level parosmia, which is typically more severe, and recent parosmia reports during the COVID-19 pandemic, where long-term outcomes are still unknown.

Growing evidence indicates that air pollution can negatively impact cognitive functions. The olfactory system is interesting in this context as it is directly exposed to pollutants and also associated with cognitive functions. The aim of this study was to investigate long- and short-term PM

Aims Health literacy, the degree to which individuals understand and act upon health information, may have a pivotal role in the prevention of cardiovascular disease (CVD), with low health literacy potentially explaining poorer adherence to prevention guidelines. We investigated the associations between health literacy, ultrasound-detected carotid atherosclerosis and cardiovascular risk factors. Methods Baseline data (cross-sectional analysis) from a randomized controlled trial, integrated within the Västerbotten Intervention Program, Northern Sweden, was used. We included 3459 individuals, aged 40 or 50 years with ≥1 conventional risk factor or aged 60 years old. The participants underwent clinical examination, blood sampling, carotid ultrasound assessment of intima-media wall thickness (CIMT) and plaque formation, and answered a questionnaire on health literacy – the Brief Health Literacy Screen. The European Systematic Coronary Risk Evaluation and Framingham Risk Score were calculated. Results About 20% of the participants had low health literacy. Low health literacy was independently associated with the presence of ultrasound-detected carotid artery plaques after adjustment for age and education, odds ratio (95% confidence interval) 1.54 (1.28–1.85), demonstrating a similar level of risk as for smoking. Health literacy was associated with CIMT in men. Low health literacy was associated with higher CVD risk scores. Sensitivity analyses with low health literacy set to 9% or 30% of the study sample, respectively, yielded essentially the same results. Conclusions Low health literacy was independently associated with carotid artery plaques and a high level of CVD risk scores. Presenting health information in a fashion that is understood by all patients may improve preventive efforts.

Parosmia, experiences of distorted smell sensations, is a common consequence of covid-19. The phenomenon is not well understood in terms of its impact and long-term outcomes. We examined parosmia in a population-based sample from the Betula study that was conducted in Umeå in northern Sweden (baseline data collected in 1998-2000). We used a baseline sample of 2168 individuals aged 35-90 years and with no cognitive impairment at baseline. We investigated the prevalence of parosmia and, using regression analyses, its relationship to other olfactory and cognitive variables and quality of life. Benefitting from the longitudinal study design, we also assessed the persistence of parosmia over 5 and 10 years prospectively. Parosmia was prevalent in 5% of the population (n=104) and was often co-occurring with phantosmia (“olfactory hallucinations”), but was not associated with lower self-rated overall quality of life or poor performance on olfactory or cognitive tests. For some individuals, parosmia was retained 5 years (17%) or even 10 years later (10%). Thus, parosmia is relative common in the population, and can be persistent for some individuals. This work provides rare insights into the expected impact of, and recovery from parosmia, with implications for those suffering from qualitative olfactory dysfunction following covid-19.

The origin of idiopathic environmental intolerances (IEIs) is an open question. According to the psychological approaches, various top-down factors play a dominant role in the development of IEIs. The general psychopathology model assumes a propensity towards mental ill-health (negative affectivity) increases the probability of developing IEIs. The attribution model emphasizes the importance of mistaken attribution of experienced somatic symptoms; thus, more symptoms should lead to more IEIs. Finally, the nocebo model highlights the role of expectations in the development of IEIs. In this case, worries about the harmful effects of environmental factors are assumed to evoke IEIs. We estimated cross-lagged panel models with latent variables based on longitudinal data obtained at two time points (six years apart) from a large near-representative community sample to test the hypothesized associations. Indicators of chemical intolerance, electromagnetic hypersensitivity, and sound sensitivity fit well under a common latent factor of IEIs. This factor, in turn, showed considerable temporal stability. However, whereas a positive association was found between IEIs and increased somatic symptoms and modern health worries six years later, the changes therein could not be predicted as hypothesized by the three psychological models. We discuss the implications of these results, as well as methodological aspects in the measurement and prediction of change in IEIs.

Olfaction, the sense of smell, is characterized by a notable age-dependency such that aging individuals are more likely to have poor olfactory abilities. These impairments are considered to be mostly irreversible and as having potentially profound effects on quality of life and food behavior, as well as constituting warning signs of mortality, cognitive dysfunction, and dementia. Here, we review the current state of research on aging and olfaction, focusing on five topics which we regard to be of particular relevance for the field: nutrition and health, cognition and dementia, mortality, environment and genetics, and training-based enhancement. Under each of these headlines, we provide a state-of-the-art overview and discuss gaps in our knowledge which might be filled by further research. Understanding how olfactory abilities are diminished in aging, and how they may be alleviated or recovered, involves a set of challenging tasks for researchers in the years to come.

Despite sleep disturbance and somatic symptoms being common health complaints, the relationship between these disturbances and single somatic symptoms is not well documented. The objectives of this study were to (i) identify somatic symptoms that are particularly associated with sleep disturbance, here referred to as somatic symptoms related to sleep disturbance (SS-SD), (ii) determine increased risk of sleep disturbance for each SS-SD and for a certain number of SS-SD, with and without controlling for anxiety and depression, and (iii) determine sensitivity and specificity for identifying sleep disturbance based on number of SS-SD in a general Swedish sample. Population-based, cross-sectional data based on validated questionnaire instruments were used from participants who constituted a sleep disturbance (n = 864) or a reference (n = 2340) group. Among 15 common somatic symptoms, stomach pain, back pain nausea/gas/indigestion, dizziness, and constipation/loose bowels/diarrhea were identified as SS-SD, with odds ratios of increased risk of sleep disturbance that ranged from 1.93 to 2.44 (1.36–1.79 and 1.54–1.91 when controlled for anxiety and depression, respectively). The risk of sleep disturbance increased by 1.44 times for each SS-SD (1.25 and 1.30 when controlled for anxiety and depression, respectively). A cutoff of two/three or more SS-SD had a sensitivity of 72.5/54.2% and a specificity of 50.0/69.7% for identifying sleep disturbances. When patients present with these somatic symptoms with or without a pathophysiological explanation, primary care clinicians may consider screening for sleep disturbance.

Purpose: The purpose was to develop a questionnaire instrument to measure difficulties in activities and participation, and impact of environmental factors in chemical intolerance, based on the International Classification of Functioning, Disability and Health, and to assess its validity and reliability. Method: Development in three steps: (1) choosing items of relevance for chemical intolerance with an expert group, (2) conducting interviews with persons with chemical intolerance, using sampling to redundancy, (3) conducting a survey with 112 respondents at a first assessment and 91 at a second assessment for test-retest. Results: The final version of the instrument consists of 57 items divided in three parts, which showed good internal consistency in each part, Cronbach alpha: 0.73–0.87. It had good content validity, readability and face validity. Test-retest showed good to very good (≥0.61) Kappa agreement for 37 items, and moderate (0.41–0.60) for 17 items. Three items had poor or fair (Conclusion: The instrument was found to be valid and reliable. It can be used as a clinical tool to help persons with chemical intolerance to receive the best suited help and support for each individual, identify key points in rehabilitation, measure rehabilitation outcome and establish priority for treatment.IMPLICATIONS FOR REHABILITATIONThe questionnaire instrument based on the International Classification of Functioning, Disability and Health which was developed and evaluated in this study, can be used to measure difficulties in activities and participation, and impact of environmental factors in chemical intolerance.Persons with chemical intolerance report lack of support from healthcare and society. Using this questionnaire instrument can help forming the best suited help and support for each individual based on his/her preconditions.This questionnaire instrument can be used to identify key points in rehabilitation and measure rehabilitation outcome. The questionnaire instrument based on the International Classification of Functioning, Disability and Health which was developed and evaluated in this study, can be used to measure difficulties in activities and participation, and impact of environmental factors in chemical intolerance. Persons with chemical intolerance report lack of support from healthcare and society. Using this questionnaire instrument can help forming the best suited help and support for each individual based on his/her preconditions. This questionnaire instrument can be used to identify key points in rehabilitation and measure rehabilitation outcome.

Growing evidence indicates that air pollution can negatively impact cognitive functions. The olfactory system is interesting in this context as it is directly exposed to pollutants and also associated with cognitive functions. The aim of this study was to investigate long- and short-term PM2.5 exposure in association with olfactory functions. Scores from odor tests were obtained from the Betula project - a longitudinal cohort study. Estimates of annual mean PM2.5 concentrations at the participants' residential address were obtained from a dispersion-model. Daily mean PM2.5 concentrations were obtained from a measuring station close to the test location. We found a positive association between long-term PM2.5 exposure and odor identification, i.e. exposure was associated with a better ability to identify odors. We also found an interaction effect between PM2.5 and age on odor identification. We found no associations between any PM2.5 exposure and odor detection or between short-term PM2.5 exposure and olfactory functions.

BACKGROUND: Primary prevention of cardiovascular disease often fails because of poor adherence among practitioners and individuals to prevention guidelines. We aimed to investigate whether ultrasou ...

Purpose: We investigated the association between hyperacusis and aspects of psychosocial work environment in a general population. The objectives were to investigate (1) prevalence and characteristics (among age, sex, access to social support at home, education, smoking, physical exercise, and perceived general health) of hyperacusis in a general working population and (2) associations between hyperacusis and psychosocial factors in the work environment. The psychosocial work aspects included effort, reward, overcommitment, worry, and social and emotional support. Methods: Using data from a sample stratified for age and sex from the Österbotten Environmental Health Study in Finland, currently employed participants with self-reported hyperacusis and referents were compared on questionnaire instruments quantifying six aspects of their psychosocial work environment. Results: Among 856 currently employed participants, 47 constituted a hyperacusis group and 809 a reference group. The hyperacusis group scored significantly higher than the referents on worry at work, social support at work, and reward at work, but not on emotional support at work, work overcommitment, or effort at work. About 40% of the hyperacusis group scored on the upper quartile of the three former work environment factors, with odds ratios ranging from 1.91 to 2.56. Conclusions: The results suggest that worrying about aspects at work, perceiving low social support, and not perceiving being rewarded at work are associated with hyperacusis.

This study investigated comorbidity in chemical intolerance (CI) and building- related intolerance (BRI) with (i) chronic sinusitis, chronic obstructive pulmonary disease, allergic and nonallergic asthma and allergic rhinitis, and (ii) airway inflammatory symptoms.Data from two population-based questionnaire surveys, the Västerbotten and Österbotten Environmental Health Studies, were used. The participants were categorized as CI or BRI and referents, and binary logistic regression analysis was applied.Prevalence rates for the case groups were 7.2% to 40.0% for diseases and 24.3% to 68.9% for symptoms, whereas adjusted odds ratios (ORs) were 3.4 to 26.1 for diseases and 3.3 to 17.0 for symptoms, all being significantly higher than unity. Prevalence rates and ORs were in general higher in BRI than in CI.Inflammatory airway diseases and symptoms are associated with CI and BRI, which encourages further research regarding underlying mechanisms and treatments.

We identified optimal cutoff scores for three questionnaire instruments that quantify environmental annoyance (affective reactions and behavioral disruptions) attributed to everyday environmental e ...

To determine the prevalence of various environmental intolerances (EIs), using several criteria in a Swedish and a Finnish general population. Ill-health attributed to low-level environmental exposures is a commonly encountered challenge in occupational and environmental medicine.In population-based questionnaire surveys, the Västerbotten Environmental Health Study (Sweden) and the Österbotten Environmental Health Study (Finland), EI was inquired by one-item questions on symptom attribution to chemicals, certain buildings, or electromagnetic fields (EMFs), and difficulties tolerating sounds. The respondents were asked whether they react with central nervous system (CNS) symptoms or have a physician-diagnosed EI attributed to the corresponding exposures. Prevalence rates were determined for different age and sex groups and the Swedish and Finnish samples in general.In the Swedish sample (n = 3406), 12.2% had self-reported intolerance to chemicals, 4.8% to certain buildings, 2.7% to EMFs, and 9.2% to sounds. The prevalence rates for the Finnish sample (n = 1535) were 15.2%, 7.2%, 1.6%, and 5.4%, respectively, differing statistically significantly from the Swedish. EI to chemicals and certain buildings was more prevalent in Finland, while EI to EMFs and sounds more prevalent in Sweden. The prevalence rates for EI with CNS-symptoms were lower and physician-diagnosed EIs considerably lower than self-reported EIs. Women reported EI more often than men and the young (18-39 years) to a lesser degree than middle-aged and elderly.The findings reflect the heterogeneous nature of EI. The differences in EI prevalence between the countries might reflect disparities concerning which exposures people perceive harmful and focus their attention to.

Chemical intolerance is a medically unexplained affliction that implies deleterious reactions to non-toxic everyday chemical exposure. Sensitization (i.e. increased reactivity to repeated, invariant stimulation) to odorous stimulation is an important component in theoretical explanations of chemical intolerance, but empirical evidence is scarce. We hypothesized that (1) individuals who sensitize to repeated olfactory stimulation, compared with those who habituate, would express a lower blood oxygenated level dependent (BOLD) response in key inhibitory areas such as the rACC, and higher signal in pain/saliency detection regions, as well as primary and/or secondary olfactory projection areas; and (2) olfactory sensitization, compared with habituation, would be associated with greater self-reported chemical intolerance. Moreover, we assessed whether olfactory sensitization was paralleled by comparable trigeminal processing - in terms of perceptual ratings and BOLD responses. We grouped women from a previous functional magnetic imaging study based on intensity ratings of repeated amyl acetate exposure over time. Fourteen women sensitized to the exposure, 15 habituated, and 20 were considered "intermediate" (i.e. neither sensitizers nor habituaters). Olfactory sensitizers, compared with habituaters, displayed a BOLD-pattern in line with the hypothesis, and reported greater problems with odours in everyday life. They also expressed greater reactions to CO

To determine whether dementia could explain the association between poor olfactory performance and mortality risk within a decade-long follow-up period.Prospective cohort study.Betula Study, Umeå, Sweden.A population-based sample of adult participants without dementia at baseline aged 40 to 90 (N = 1,774).Olfactory performance using the Scandinavian Odor-Identification Test (SOIT) and self-reported olfactory function; several social, cognitive, and medical risk factors at baseline; and incident dementia during the following decade.Within the 10-year follow-up, 411 of 1,774 (23.2%) participants had died. In a Cox model, the association between higher SOIT score and lower mortality was significant (hazard ratio (HR) = 0.74 per point interval, 95% confidence interval (CI) = 0.71-0.77, P.001). The effect was attenuated, but remained significant, after controlling for age, sex, education, and health-related and cognitive variables (HR = 0.92, 95% CI = 0.87-0.97, P = .001). The association between SOIT score and mortality was retained after controlling for dementia conversion before death (HR = 0.92, 95% CI = 0.87-0.97, P = .001). Similar results were obtained for self-reported olfactory dysfunction.Poor odor identification and poor self-reported olfactory function are associated with greater likelihood of future mortality. Dementia does not attenuate the association between olfactory loss and mortality, suggesting that olfactory loss might mark deteriorating health, irrespective of dementia.

Indoor air health problems of the type non-specific building-related symptoms (NBRS; formally called "sick-building syndrome") and chemical intolerance (CI; e.g. multiple chemical sensitivity) can in severe cases lead to significant disability and poor quality of life. Apart from suffering of the afflicted individuals, the productivity loss ascribed to environmental intolerances of this kind is very costly for society. Preventive measures and appropriate treatment call for understanding of the mechanism underlying NBRS and CI. Considerable similarities between NBRS and CI suggest that the two conditions at large share mechanisms. Since typical cases of these conditions cannot be explained by toxic exposure, the present objective is to describe underlying mechanisms of psychobiological nature for which there is well-developed theoretical ground and empirical support. Focus lies on the mechanisms neurogenic inflammation and neural sensitization. Apart from describing its basic mechanisms, neurogenic inflammation is reviewed in relation to NBRS and CI regarding neurogenic switching, activation of the autonomic nervous system and axon reflex as well as interaction effects between chemical irritants, allergens, and psychosocial stressors. In addition to describing various types of sensitization, empirical support for their role in NBRS and CI is reviewed. The mechanism classical conditioning, symptom misattribution and somatosensory amplification, and nocebo are also addressed. The review rounds off with a discussion on why only a subset of individuals exposed to these indoor environments develop NBRS and CI, and a discussion on integration of the presented mechanisms, accompanied by proposed hypotheses for future research. HUSS

Background Taking a broad approach, the aim of this study was to better understand severity and prevalence of various types of mental ill-health across age and sex groups in the general adult population. A first objective was to determine symptom severity of anxiety, depression, insomnia, burnout and somatization in combinations of different age groups and sex. A second objective was to determine prevalence of caseness of these types of mental ill-health in both absolute and relative terms in the combinations of age groups and sex. Methods Cross-sectional data based on validated questionnaire instruments were used from the Västerbotten Environmental Health Study in Sweden. In total, 3406 participants, aged 18 to 79 years, constituted a random sample stratified for age and sex. Results Severity and prevalence of anxiety, insomnia and burnout were high in women, in particular young women, and lower in older age groups. The prevalence rates for insomnia, burnout and somatization were particularly high based on the used cut-off scores. Men aged 30–49 years had the highest prevalence of mental ill-health compared to other age groups among men. Men and women aged 60–69 years had generally the lowest symptom severity and caseness. The prevalence of depression was similar in men and women in all age groups, whereas sex-related differences in extent in general were largest in the youngest age group, and gradually decreased with age. Conclusion The results suggest that focus in primary healthcare regarding mental ill-health should to be directed more towards insomnia, burnout and somatization, in particular in young women.

Modern health worries (MHWs) refer to people's concerns about possible harmful effects of modern technologies, and are widespread in the developed countries. The aim of the present work was to provide comprehensive, yet integrated understanding for MHWs and associated factors.Following the PRISMA guideline, a systematic review was conducted based on 48 empirical articles published between 2001 and 2018 (Prospero registration number: CRD42018103756). All empirical studies were included that (1) were published between 2001 and 2018 in peer-reviewed scientific journals in English, German, or Hungarian, (2) used the Modern Health Worries Scale or any of its sub-scales, and (3) assessed associations between MHWs and other constructs and/or compared criterion groups (i.e. purely psychometric studies were excluded).The results from the review suggest that female gender, age, somatic symptom distress and idiopathic environmental intolerances, holistic thinking, and paranoid beliefs are positively associated with MHWs, whereas educational qualification and the five major dimensions of personality appear not to be.Scientific inquiry on the MHWs phenomenon is still in its descriptive-explorative phase; more rigorously designed studies are needed. The presented theoretical framework integrates illness-related and holistic thinking-related aspects of MHWs as a starting point to guide further research in this area.

The aim was to gain understanding for the impact of negative affectivity (NA) and odor valance on perceptual aspects during low-level odorous exposure. Fifty-five young adults who were either relatively low or high in NA (anxiety, depression, and somatization) were randomized for exposure to either limonene (pleasant odor) or pyridine (unpleasant odor). In an exposure chamber, they took part in baseline, blank and stable exposure sessions, during which they rated odor intensity, impact on ability to focus on an imagined cognitive task, and intensity of symptoms. The results showed higher ratings of negative impact on ability to focus during exposure to the unpleasant odor compared with the pleasant odor, and an association between NA and symptom intensity, with 18% of the variance in symptom intensity explained by somatization. The association between NA and symptom intensity was found to be driven by the factor sex. These results imply (a) that prior findings of odorous exposure that interfere negatively with work performance may be due to impact of an unpleasant odor on ability to focus on cognitive tasks and (b) that there are associations between NA, sex, and symptoms that may partly be referred to attentiveness to and interpretation of bodily sensations.

Nonspecific building-related symptoms (NBRS) is a combination of general, skin and mucosal symptoms related to certain buildings. Despite high prevalence in the general population and severe symptomatology in certain cases there is no scientific documentation of quality of life in NBRS. The purpose of this study was to illuminate how individuals with NBRS experience daily life. Data were collected through descriptive, written texts and through telephone interviews with 11 individuals diagnosed with NBRS, and qualitative content analysis was conducted. Three main content areas were identified: (1) attitudes from the surrounding (categories: being questioned and lack of understanding from others; from zero to full support); (2) consequences (difficulties with daily activities; financial difficulties; affecting family and friends; emotional consequences); and (3) coping (learning to accept and finding solutions; avoiding; struggling; finding the positive; making one's home a sanctuary). As a conclusion, NBRS may affect several aspects of daily life, resulting in considerable alterations, limitations and emotional impact for the afflicted person and his/her family. Both environmental factors and attitudes from the surrounding can contribute to this impact on daily life. Strategies needed to cope with this impact may include both problem-focused and emotion-focused strategies, such as struggling, avoiding trigger factors and finding positive aspects.