Network dynamics of depressive symptoms in antidepressant medication treatment: secondary analysis of eight clinical trials.

Depression can be viewed as a network of depressive symptoms that tend to reinforce each other via feedback loops. Specific symptoms of depression may be differently responsive to antidepressant treatment, and some symptoms may be more important than others in the overall improvement of depression associated with treatment. We pooled prospective data from eight industry-sponsored placebo-controlled trials for paroxetine, fluoxetine and imipramine (total n = 3559) to examine whether improvements in specific depressive symptoms were more strongly related to improvements in other depressive symptoms among patients on active antidepressant treatment as compared to placebo. Depressive symptoms were assessed with the 17-item Hamilton Depression Rating Scale. Data on treatment was dichotomized into active treatment (receiving any antidepressant agent) vs. placebo. Time-lagged longitudinal analyses suggested that improvement in three symptoms-depressed mood, insomnia, and suicidality-had a broader overall impact on subsequent improvement in other depressive symptoms in the antidepressant condition compared to placebo (i.e., greater out-strength). Moreover, improvements in depressed mood and insomnia were more likely to follow the improvements in other symptoms in the antidepressant condition compared to placebo (i.e., greater in-strength). These results from clinical trial data suggest that depressed mood, insomnia, and suicidality may be particularly important in accounting for the remission and recovery in response to antidepressant treatment.

Association of depressive symptoms with health care utilization in older adults: Longitudinal evidence from the Survey of Health, Aging, and Retirement in Europe.

OBJECTIVES: Many older adults with depression do not receive adequate treatment. Differences in treatment utilization may reflect the heterogeneous nature of depression, encompassing multiple distinct symptoms. We assessed whether depressive symptoms are differentially associated with subsequent health care utilization with respect to three outcomes as follows: (1) contact with a medical doctor (MD), (2) depression-specific treatment, and (3) inpatient psychiatric admission. METHODS/DESIGN: Longitudinal analyses were based on data from three follow-up cycles conducted between 2004 and 2013 among 53,139 participants from the Survey of Health, Aging, and Retirement in Europe. Depressive symptoms were self-reported at baseline of each follow-up cycle using the 12-item EURO-D scale. Health care utilization was self-reported at the end of each follow-up cycle. RESULTS: After adjustment for sex, age, country of interview, follow-up time, educational attainment, presence of a partner in household, body-mass index, the number of chronic diseases, disability, average/prior frequency of contact with an MD, and all other depressive symptoms, people with more frequent contact with an MD had most often reported sleep problems (IRR = 1.10) and fatigue (IRR = 1.10), followed by sad/depressed mood, tearfulness, concentration problems, guilt, irritability, and changes in appetite. Those treated for depression had most often reported sad/depressed mood (OR = 2.18) and suicidal ideation (OR = 1.72), but also sleep problems, changes in appetite, fatigue, concentration problems, hopelessness, and irritability. Sad/depressed mood (OR = 2.87) was also associated with psychiatric inpatient admission. Similarly to other outcomes, appetite change, fatigue, and sleep problems were associated with inpatient admission. CONCLUSIONS: Specific symptoms of depression may determine utilization of different types of health care among elderly.

Subclinical hypothyroidism and symptoms of depression: Evidence from the National Health and Nutrition Examination Surveys (NHANES).

BACKGROUND: Subclinical hypothyroidism has been associated with increased risk for depression, yet the findings remain controversial. It is possible that subclinical hypothyroidism is associated with some, but not all symptoms of depression. We examined symptom-specific associations between depression and subclinical hypothyroidism. METHODS: Participants (N = 7683 adults) were from the National Health and Nutrition Examination Surveys of 2007-2008, 2009-2010, and 2011-2012 We included participants who had data on their thyroid profile and depressive symptoms (measured using Patient Health Questionnaire), and excluded those with overt hypothyroidism or hyperthyroidism, and those on thyroid hormone replacement therapy. Logistic regression with sampling weights was used to examine the association between subclinical hypothyroidism and depression symptoms. We also ran sensitivity analysis using different cut-off points for defining subclinical hypothyroidism. RESULTS: Of all the participants, 208 (2.7%) had subclinical hypothyroidism and of them only six had depression. Subclinical hypothyroidism was not associated with depression (OR = 0.61, 95% CI 0.20-1.87) nor with the specific depression symptoms. Using lower criteria for subclinical hypothyroidism diagnosis resulted in similar findings. CONCLUSIONS: In a nationally representative sample of US adults, we observed no association between subclinical hypothyroidism and overall depression risk or any of the individual symptoms of depression.

Health behaviors and psychological distress: changing associations between 1997 and 2016 in the United States.

OBJECTIVES: Smoking rates have declined with a slower pace among those with psychological distress compared to those without. We examined whether other health behaviors (heavy alcohol consumption, physical inactivity, short sleep duration) showed similar trends associated with psychological distress. We also examined differences by age and birth cohort. METHODS: Data were from the annually repeated cross-sectional U.S. National Health Interview Surveys (NHIS) of 1997-2016 (total n = 603,518). Psychological distress was assessed with the 6-item Kessler Psychological Distress Scale (K6). RESULTS: Psychological distress became more strongly associated with smoking (OR 1.09 per 10 years; 95% CI 1.07, 1.12), physical inactivity (OR 1.08; 1.05, 1.11), and short sleep (OR 1.12; 1.06, 1.18), but less strongly associated with heavy alcohol consumption (OR 0.93; 0.89, 0.98). The associations of smoking and alcohol consumption attenuated with age, whereas the association with physical inactivity strengthened with age. Compared to older birth cohorts, smoking became more strongly associated with psychological distress among younger birth cohorts up to those born in the 1980s. CONCLUSIONS: The strength of associations between psychological distress and health behaviors may vary by time period, age, and birth cohort.

Personality, disability-free life years, and life expectancy: Individual participant meta-analysis of 131,195 individuals from 10 cohort studies.

OBJECTIVE: We examined how personality traits of the Five Factor Model were related to years of healthy life years lost (mortality and disability) for individuals and the population. METHOD: Participants were 131,195 individuals from 10 cohort studies from Australia, Germany, the United Kingdom, and the United States (n = 43,935 from seven cohort studies for the longitudinal analysis of disability, assessed using scales of Activities of Daily Living). RESULTS: Lower Conscientiousness was associated with higher mortality and disability risk, but only when Conscientiousness was below its median level. If the excess risk associated with low Conscientiousness had been absent, population life expectancy would have been 1.3 years longer and disability-free life 1.0 years longer. Lower emotional stability was related to shorter life expectancy, but only among those in the lowest 15% of the distribution, and disability throughout the distribution: if the excess risk associated with low emotional stability had been absent, population life expectancy would have been 0.4 years longer and disability-free life 2.4 years longer. CONCLUSIONS: Personality traits of low Conscientiousness and low emotional stability are associated with reduced healthy life expectancy of individuals and population.

Moving on: How depressive symptoms, social support, and health behaviors predict residential mobility.

BACKGROUND: There are major health inequalities between residential areas. However, it remains unclear whether these inequalities are due to social causation or selective residential mobility, because little is known about the associations between health-related factors and selective residential mobility. This study examined how depressive symptoms, social support, and health behaviors are associated with subsequent residential mobility, as measured by frequency, distance, and direction of moves. METHODS: Participants were selected from the Young Finns prospective cohort study (N = 3017) with four study waves in 1992, 1997, 2001, and 2007. Complete residential mobility history was gathered for each participant from registry data. Residential mobility was assessed over three-year periods following each study wave. The direction of mobility was measured as changes in residential location's population density, health index, mortality index, and unemployment. Area characteristics were used as covariates together with the participants' age, sex, and education. RESULTS: Individuals reporting higher social support from friends were more likely to move (b = 0.20; 95% confidence interval (CI): 0.08, 0.37) and move more frequently (b = 0.08; 95% CI: 0.01, 0.14), whereas individuals reporting higher social support from their family members were less likely to move (b = -0.08; 95% CI: -0.14, -0.02). Better health behaviors were associated with longer moving distances (b = 0.14; 95% CI: 0.06, -0.23). None of the individual characteristics were associated with the direction of moves as measured by changes in municipality characteristics. CONCLUSIONS SOME OF THE HEALTH-RELATED CHARACTERISTICS ARE ASSOCIATED WITH RESIDENTIAL MOBILITY IN FINLAND HOWEVER, THESE INDIVIDUAL CHARACTERISTICS DO NOT SEEM TO PREDICT SYSTEMATIC SELECTIVE RESIDENTIAL MOBILITY ACROSS MUNICIPALITIES WITH DIFFERENT REGIONAL HEALTH PROFILES.

Neighbourhood effects in health behaviours: a test of social causation with repeat-measurement longitudinal data.

BACKGROUND: Neighbourhood characteristics have been associated with health behaviours of residents. We used longitudinal data to examine whether neighbourhood characteristics (level of urbanization and socioeconomic status) are related to within-individual variations in health behaviours (alcohol consumption, smoking, exercise and self-interest in health) as people live in different neighbourhoods over time. METHODS: Participants were from the Young Finns prospective cohort study (N = 3145) with four repeated measurement times (1992, 2001, 2007 and 2011/2012). Neighbourhood socioeconomic status and level of urbanization were measured on the level of municipality and zip code area. Within-individual (i.e. fixed-effect) regression was used to examine whether these associations were observed within individuals who lived in different neighbourhood in different measurement times. RESULTS: People living in more urban zip code areas were more likely to smoke (b = 0.06; CI = 0.03-0.09) and drink alcohol (b = 0.11; CI = 0.08-0.14), and these associations were replicated in within-individual analysis-supporting social causation. Neighbourhood socioeconomic status and urbanization were associated with higher interest in maintaining personal health (b = 0.05; CI = 0.03-0.08 and b = 0.05; CI = 0.02-0.07, respectively), and these associations were also similar in within-individual analysis. Physical exercise was not associated with neighbourhood characteristics. CONCLUSIONS: These data lend partial support for the hypothesis that neighbourhood differences influence people's health behaviours.

Prediction of violence or threat of violence among employees in social work, healthcare and education: the Finnish Public Sector cohort study.

OBJECTIVES: To develop a risk prediction algorithm for identifying work units with increased risk of violence in the workplace. DESIGN: Prospective cohort study. SETTING: Public sector employees in Finland. PARTICIPANTS: 18 540 nurses, social and youth workers, and teachers from 4276 work units who completed a survey on work characteristics, including prevalence and frequency of workplace violence/threat of violence at baseline in 2018-2019 and at follow-up in 2020-2021. Those who reported daily or weekly exposure to violence or threat of violence daily at baseline were excluded. EXPOSURES: Mean scores of responses to 87 survey items at baseline were calculated for each work unit, and those scores were then assigned to each employee within that work unit. The scores measured sociodemographic characteristics and work characteristics of the work unit. PRIMARY OUTCOME MEASURE: Increase in workplace violence between baseline and follow-up (0=no increase, 1=increase). RESULTS: A total of 7% (323/4487) of the registered nurses, 15% (457/3109) of the practical nurses, 5% of the social and youth workers (162/3442) and 5% of the teachers (360/7502) reported more frequent violence/threat of violence at follow-up than at baseline. The area under the curve values estimating the prediction accuracy of the prediction models were 0.72 for social and youth workers, 0.67 for nurses, and 0.63 for teachers. The risk prediction model for registered nurses included five work unit characteristics associated with more frequent violence at follow-up. The model for practical nurses included six characteristics, the model for social and youth workers seven characteristics and the model for teachers included four characteristics statistically significantly associated with higher likelihood of increased violence. CONCLUSIONS: The generated risk prediction models identified employees working in work units with high likelihood of future workplace violence with reasonable accuracy. These survey-based algorithms can be used to target interventions to prevent workplace violence.

Prediction of bullying at work: A data-driven analysis of the Finnish public sector cohort study.

AIM: To determine the extent to which change in (i.e., start and end of) workplace bullying can be predicted by employee responses to standard workplace surveys. METHODS: Responses to an 87-item survey from 48,537 Finnish public sector employees at T1 (2017-2018) and T2 (2019-2020) were analyzed with least-absolute-shrinkage-and-selection-operator (LASSO) regression. The predictors were modelled both at the individual- and the work unit level. Outcomes included both the start and the end of bullying. Predictive performance was evaluated with C-indices and density plots. RESULTS: The model with best predictive ability predicted the start of bullying with individual-level predictors, had a C-index of 0.68 and included 25 variables, of which 6 remained in a more parsimonious model: discrimination at work unit, unreasonably high workload, threat that some work tasks will be terminated, working in a work unit where everyone did not feel they are understood and accepted, having a supervisor who was not highly trusted, and a shorter time in current position. Other models performed even worse, either from the point of view of predictive performance, or practical useability. DISCUSSION: While many bivariate associations between socioeconomic characteristics, work characteristics, leadership, team climate, and job satisfaction were observed, reliable individualized detection of individuals at risk of becoming bullied at workplace was not successful. The predictive performance of the developed risk scores was suboptimal, and we do not recommend their use as an individual-level risk prediction tool. However, they might be useful tool to inform decision-making when planning the contents of interventions to prevent bullying at an organizational level.

Predicting work disability among people with chronic conditions: a prospective cohort study.

Few risk prediction scores are available to identify people at increased risk of work disability, particularly for those with an existing morbidity. We examined the predictive performance of disability risk scores for employees with chronic disease. We used prospective data from 88,521 employed participants (mean age 43.1) in the Finnish Public Sector Study including people with chronic disorders: musculoskeletal disorder, depression, migraine, respiratory disease, hypertension, cancer, coronary heart disease, diabetes, comorbid depression and cardiometabolic disease. A total of 105 predictors were assessed at baseline. During a mean follow-up of 8.6 years, 6836 (7.7%) participants were granted a disability pension. C-statistics for the 8-item Finnish Institute of Occupational Health (FIOH) risk score, comprising age, self-rated health, number of sickness absences, socioeconomic position, number of chronic illnesses, sleep problems, BMI, and smoking at baseline, exceeded 0.72 for all disease groups and was 0.80 (95% CI 0.80-0.81) for participants with musculoskeletal disorders, 0.83 (0.82-0.84) for those with migraine, and 0.82 (0.81-0.83) for individuals with respiratory disease. Predictive performance was not significantly improved in models with re-estimated coefficients or a new set of predictors. These findings suggest that the 8-item FIOH work disability risk score may serve as a scalable screening tool in identifying individuals with increased risk for work disability.

Predicting long-term sickness absence with employee questionnaires and administrative records: a prospective cohort study of hospital employees.

OBJECTIVE: This study aimed to compare the utility of risk estimation derived from questionnaires and administrative records in predicting long-term sickness absence among shift workers. METHODS: This prospective cohort study comprised 3197 shift-working hospital employees (mean age 44.5 years, 88.0% women) who responded to a brief 8-item questionnaire on work disability risk factors and were linked to 28 variables on their working hour and workplace characteristics obtained from administrative registries at study baseline. The primary outcome was the first sickness absence lasting ≥90 days during a 4-year follow-up. RESULTS: The C-index of 0.73 [95% confidence interval (CI) 0.70-0.77] for a questionnaire-only based prediction model, 0.71 (95% CI 0.67-0.75) for an administrative records-only model, and 0.79 (95% CI 0.76-0.82) for a model combining variables from both data sources indicated good discriminatory ability. For a 5%-estimated risk as a threshold for positive test results, the detection rates were 76%, 74%, and 75% and the false positive rates were 40%, 45% and 34% for the three models. For a 20%-risk threshold, the corresponding detection rates were 14%, 8%, and 27% and the false positive rates were 2%, 2%, and 4%. To detect one true positive case with these models, the number of false positive cases accompanied varied between 7 and 10 using the 5%-estimated risk, and between 2 and 3 using the 20%-estimated risk cut-off. The pattern of results was similar using 30-day sickness absence as the outcome. CONCLUSIONS: The best predictive performance was reached with a model including both questionnaire responses and administrative records. Prediction was almost as accurate with models using only variables from one of these data sources. Further research is needed to examine the generalizability of these findings.

A measure for assessment of beneficial and harmful fortitude: development and initial validation of the Sisu Scale.

Sisu is a Finnish cultural concept that denotes determination and resoluteness in the face of adversity. We propose that sisu will supplement the English-language based research on mental fortitude traits. Sisu has not been the focus of systematic research until very recently. We created a new questionnaire measuring sisu (the Sisu Scale), sought to validate the sisu construct and its sub-factor structure as postulated in a recent qualitative study. We investigated associations of sisu with other measures of mental fortitude and well-being. More generally we aimed to enrichen the cross-cultural understanding of human experience of overcoming adversity across life's challenges. We describe and validate a questionnaire that effectively measures both beneficial and harmful sisu, each comprising three sub-factors. Beneficial sisu was associated with other measures of fortitude, but less with personality dimensions. We also confirmed the existence of an independent harmful sisu factor. Beneficial sisu was associated with higher well-being and lower depressive symptoms, and harmful sisu with lower well-being and higher levels of general stress, work stress and depressive symptoms. Together the two factors were superior compared to pre-existing measures when predicting well-being-related variables. Results suggest that the new Sisu Scale we developed may provide a valuable addition to research on mental fortitude, resilience and their consequences for well-being.

Big Five personality traits and COVID-19 precautionary behaviors among older adults in Europe.

OBJECTIVES: Taking precautions against COVID-19 is important among older adults who have a greater risk for severe illness if infected. We examined whether Big Five personality traits are associated with COVID-19 precautionary behaviors among older adults in Europe. METHOD: We used data from the Survey of Health, Aging, and Retirement in Europe (N = 34 629). Personality was self-reported in 2017 using the BFI-10 inventory. COVID-19 precautionary behaviors - wearing a mask, limiting in-person contacts, keeping a distance to others, washing hands, and using a disinfectant - were assessed in the summer of 2020 through self-reports. Associations between personality and precautionary behaviors were examined with multilevel random-intercept logistic regression models. The models were adjusted for age, gender, and educational attainment. RESULTS: Personality traits were differentially associated with precautionary behaviors, with higher openness, conscientiousness, and neuroticism showing the most consistent associations. The pattern of associations between personality traits and precautionary behaviors varied depending on the specific behavior. The associations were relatively weak in comparison to those between sociodemographic factors and precautionary behaviors. CONCLUSIONS: Among older adults, taking COVID-19 precautionary behaviors was most consistently related to higher openness, conscientiousness, and neuroticism, suggesting that precautionary behaviors may be motivated by multiple psychological differences.

Testosterone and specific symptoms of depression: Evidence from NHANES 2011-2016.

Testosterone is one possible biomarker for depression risk among men and women. Both high and low levels of testosterone have been associated with depression, at least among men. Testosterone may be associated only with specific symptoms of depression, which might help to explain inconsistencies in previous results. We examined the cross-sectional associations between total testosterone and the specific symptoms of depression using pooled data across three cycles of NHANES (2011-2012, 2013-2014, and 2015-2016). The sample included 4253 men and 5102 women. Testosterone was modelled as 1) a dichotomous (low testosterone cut-off <300 â€‹ng/dL for men and 15 â€‹ng/dL for women) and 2) a continuous variable using cubic splines. In men, very low testosterone was weakly associated with problems with appetite, whereas very high testosterone was associated with sleep problems and weakly associated with tiredness. There were no consistent symptom-specific associations among women. These findings provide only suggestive evidence for symptom-specific associations between testosterone and depression, mainly related to somatic complaints. Further data are needed to assess the reliability of these associations.

Specific symptoms of the General Health Questionnaire (GHQ) in predicting persistence of psychological distress: Data from two prospective cohort studies.

Persistent psychological distress is more harmful than transient psychological distress, but little is known about the development of persistent distress. We examined whether some specific symptoms of the 12-item General Health Questionnaire (GHQ-12) were more important than others in predicting the persistence of psychological distress over a 3-year follow-up period among individuals who had at least moderate psychological distress at baseline (GHQ≥3). Participants were from the UK Household Longitudinal Study (UKHLS; n = 6430) and British Household Panel Survey (BHPS; n = 5954). Sense of worthlessness, loss of self-confidence, loss of sleep over worry, and feelings of strain were associated with increasingly persistent distress. General happiness, feelings of unhappiness or depressed mood, and enjoyment of activities showed no such increasing associations. Symptoms of social functioning (capability of making decisions, concentration problems, feelings of usefulness, ability to face problems) showed some but not consistent associations. These results suggest that feelings of worthlessness, loss of self-confidence, loss of sleep over worry, and strain may be particularly important markers for persistent psychological distress.

Socioeconomic inequalities in impairment associated with depressive symptoms: Evidence from the National Survey on Drug Use and Health.

OBJECTIVE: Individuals with low socioeconomic status have higher rates of depression, but it is unknown whether the socioeconomically disadvantaged also have more disabling depressive symptoms. We examined (1) the associations of three indicators of socioeconomic status with depression-related severe role impairment, and (2) whether socioeconomic factors moderate the association between individual depression symptoms and depression-related severe role impairment. METHODS: We used data from the National Survey on Drug Use and Health (NSDUH). Depressive symptoms, role impairment and socioeconomic indicators (poverty, participation in workforce, educational attainment) were self-reported by participants. The analytic sample consisted of participants who screened positive for a depressive episode during past 12 months (n = 32 661). We used survey-weighted logistic models to examine the associations of depressive symptoms with severe role impairment and the modifying effects of socioeconomic indicators. RESULTS: The association between depression symptom count and severe role impairment was stronger among those not in workforce (OR = 1.12[1.02-1.23]). The association between specific depression symptoms and severe role impairment was stronger for conditions of poverty (fatigue, OR = 2.97 [1.54-5.73]; and anhedonia, OR = 1.93[1.13-3.30]), workforce non-participation (inability to concentrate/indecisiveness, OR = 1.54[1.12-2.12]), and lower educational attainment (anhedonia, OR = 0.77 [0.59-0.99]). Feelings of worthlessness was the only symptom with independent associations for all socioeconomic groups (adjusted OR = 1.91[1.35-2.70]). CONCLUSION: Depression was more frequent and also more disabling for socioeconomically disadvantaged groups, especially when assessed with workforce participation. Additionally, some specific symptoms showed socioeconomic differences. Our findings highlight the need to prioritize population groups with more severe impairment associated with depressive symptoms.

Connectivity of depression symptoms before and after diagnosis of a chronic disease: A network analysis in the U.S. Health and Retirement Study.

BACKGROUND: Many chronic diseases increase the risk of depressive symptoms, but few studies have examined whether these diseases also affect the composition of symptoms a person is likely to experience. As the risk and progression of depression may vary between chronic diseases, we used network analysis to examine how depression symptoms are connected before and after the diagnosis of diabetes, heart disease, stroke, and cancer. METHODS: Participants (N = 7779) were from the longitudinal survey of the Health and Retirement Study. Participants were eligible if they had information on depression symptoms two and/or four years before and after the diagnosis of either diabetes, heart disease, cancer or stroke. We formed a control group with no chronic disease that was matched on age, sex and ethnic background to those with a disease. We constructed depression symptom networks and compared the overall connectivity of those networks, and depression symptom sum scores, for before and after the diagnosis of each disease. RESULTS: Depression symptom sum scores increased with the diagnosis of each disease. The connectivity of depression symptoms remained unchanged for all the diseases, except for stroke, for which the connectivity decreased with the diagnosis. LIMITATIONS: Comorbidity with other chronic diseases was not controlled for as we focused on the onset of specific diseases. CONCLUSIONS: Our results suggest that although the mean level of depression symptoms increases after the diagnosis of chronic disease, with most chronic diseases, these changes are not reflected in the network structure of depression symptoms.

Chronic diseases and social risk factors in relation to specific symptoms of depression: Evidence from the U.S. national health and nutrition examination surveys.

BACKGROUND: Depression is a heterogeneous mental disorder with multiple symptoms, but only few studies have examined whether associations of risk factors with depression are symptom-specific. We examined whether chronic diseases and social risk factors (poverty, divorce, and perceived lack of emotional support) are differently associated with somatic and cognitive/affective symptoms of depression. METHODS: Cross-sectional analyses were based on individual-level data from the 31,191 participants of six cross-sectional U.S. National Health and Nutrition Examination Surveys (NHANES) carried out between 2005 and 2016. Depressive symptoms were assessed using the 9-item Patient Health Questionnaire. Information on chronic diseases and social risk factors was self-reported by participants. RESULTS: After adjustment for sex, age, race/ethnicity, and all the of other symptoms besides the outcome symptom, higher number of chronic diseases was independently related to fatigue, psychomotor retardation/agitation, and sleep problems in a dose-response pattern (range of odds ratios: 1.21 to 2.59). Except for concentration problems, social risk factors were associated with almost all of the cognitive/affective symptoms (range of odds ratios: 1.02 to 2.09) but only sporadically with somatic symptoms. LIMITATIONS: All measures were self-reported by the participants, which may have introduced bias to the associations. Cross-sectional data did not allow us to study temporal dynamics. CONCLUSIONS: Specific symptoms of depression may be useful in characterizing the heterogeneous etiology of depression with respect to somatic versus social risk factors.

Does increasing physical activity reduce the excess risk of work disability among overweight individuals?

Objectives We examined the extent to which an increase in physical activity would reduce the excess risk of work disability among overweight and obese people (body mass index ≥ 25kg/m 2). Methods We used counterfactual modelling approaches to analyze longitudinal data from two Finnish prospective cohort studies (total N=38 744). Weight, height and physical activity were obtained from surveys and assessed twice and linked to electronic records of two indicators of long-term work disability (≥90-day sickness absence and disability pension) for a 7-year follow-up after the latter survey. The models were adjusted for age, sex, socioeconomic status, smoking, and alcohol consumption. Results The confounder-adjusted hazard ratio (HR) of long-term sickness absence for overweight compared to normal-weight participants was 1.43 [95% confidence interval (CI) 1.35-1.53]. An increase in physical activity among overweight compared to normal-weight individuals was estimated to reduce this HR to 1.40 (95% CI 1.31-1.48). In pseudo-trial analysis including only the persistently overweight, initially physically inactive participants, the HR for long-term sickness absence was 0.82 (95% CI 0.70-0.94) for individuals with increased physical activity compared to those who remained physically inactive. The results for disability pension as an outcome were similar. Conclusions These findings suggest that the excess risk of work disability among overweight individuals would drop by 3-4% if they increased their average physical activity to the average level of normal-weight people. However, overweight individuals who are physically inactive would reduce their risk of work disability by about 20% by becoming physically active.