Cardiorespiratory fitness and response to exercise treatment in depression

Heart rate vARiability and physical activity in inpatient treatMent of burnOut and DepressIon (HARMODI): protocol of a cross-sectional study with up to 8-week follow up

INTRODUCTION

Chronic stress can cause an imbalance within the autonomic nervous system, thereby affecting cardiovascular and mental health. Physical activity (PA) may have a positive effect on the autonomic nervous system and stress-related disorders, such as depression and burnout. Heart rate variability (HRV) is a non-invasive marker of the autonomic nervous system. However, limited and inconsistent data exist on the exact relationship between HRV, PA and depression and burnout symptoms. The HARMODI study aims to explore whether HRV is a feasible marker of depression and burnout symptoms and aims to evaluate the role of PA in the treatment of stress-related disorders.

METHODS AND ANALYSES

This is an observational study with a cross-sectional up to 8 week follow-up study design. A total of 153 patients, undergoing psychiatric inpatient treatment with burnout syndrome (Z73) and depressive episode (F32 or F33) or adjustment disorder (F43.2), will be recruited. Data on depression and burnout symptoms, HRV recordings (24-hour, supine, standing and exercise stress test), cognitive function, cardiorespiratory fitness, cardiovascular health, balance and strength will be collected at baseline (T1) and after up to 8 weeks (T2). Continuous data on PA and Ecological Momentary Assessments of exhaustion, mood and tension will be monitored daily throughout inpatient treatment. Multiple regression models, adjusted for potential confounders, will assess the association between HRV as the primary outcome, PA and depression and burnout severity score.

ETHICS AND DISSEMINATION

The protocol has been approved by Swiss Ethics Committee, Cantonal Ethics Committee Zürich. Results of HARMODI will be disseminated through peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05874856.

Cardiorespiratory fitness in midlife and subsequent incident depression, long-term sickness absence, and disability pension due to depression in 330,247 men and women

OBJECTIVE

Specific information for whom and when cardiorespiratory fitness (CRF) is associated with depression risk is lacking. We aimed to study the association between adulthood CRF and incident depression, long-term sickness absence, and disability pension due to depression, as well as examine moderation of sex, age, education, and occupation on associations.

METHODS

A large prospective cohort study follows participants over time with Swedish occupational health screenings data. The study includes 330,247 individuals (aged 16-79 years, 46% women) without a depression diagnosis at baseline. CRF was estimated from a submaximal cycle test.

RESULTS

CRF was associated beneficially from low to higher levels with incident depression and long-term sickness absence due to depression. Further, CRF at high levels (≥46 ml/min/kg) was associated with a decreased risk of receiving disability pension due to depression. The associations remained after adjustment for age and sex, but not lifestyle-related factors and co-morbidity. Participants with moderate and high CRF had 16% and 21%, respectively, lower risk for incident depression, and participants with high CRF had 11% lower risk for long-term sickness absence due to depression. Associations between higher CRF and the outcomes were mainly evident in men, younger participants, and individuals with low education.

CONCLUSION

In a large sample of adults without a depression diagnosis at baseline, higher CRF was shown to be beneficially related to the risk of incident depression and, to some extent, long-term sickness absence due to depression. If causal, targeted interventions focusing on increasing CRF in these sub-groups should be prioritized.

Self-Reported Mood and Lifestyle-Related Physical Activity of Young Adults With Major Depressive Disorder

We investigated whether mood and lifestyle-related indicators of physical health are differentially expressed according to self-reported levels of depressive symptoms among young adults with a current episode of major depression. In a cross-sectional study, we recruited 94 young adults (females = 67, 71.3%; males = 27, 28.7%; aged 18-35 years) with a current episode of major depression. We assessed their mood with the Profile of Mood States (POMS), and Beck Anxiety Inventory-(BAI), sleep with the Pittsburgh Sleep Quality Index (PSQI), physical activity with the Simple Physical Activity Questionnaire (SIMPAQ), and their cardiorespiratory fitness. Participants' depression levels were classified as follows using established cut-points: (a) Mild Depressive Symptoms (MIDS, BDI-II 14-19 points, n = 17), (b) Moderate Depressive Symptoms (MODS, BDI-II 20-28 points, n = 37) or (c) Severe Depressive Symptoms (SEDS, BDI-II 29-63 points, n = 40). As expected, we found that young adults with SEDS, when compared to those with MODS and MIDS, showed higher depressive mood on the POMS, and they exhibited greater anxiety symptoms, lower reported 'vigor' on physical activity measures, worse sleep quality as expressed by their global score sleep; daytime dysfunction; and sleep disturbance, and they showed lower cardiorespiratory fitness. Those with moderate depressive symptoms only differed from those with mild symptoms with respect to hostility, fatigue and mood disturbance. Although there was a gradient whereby worse mental and physical health indicators were more closely related to the SEDS depression categorization, while healthier indicators were associated with the MIDS category, some parameters were not different between the MDD severity groups, particularly when comparing MIDS and MODS. Clinicians treating patients with MDD should consider these factors when designing lifestyle-based interventions.

The effects of a group-based intervention through physical activities and dietary changes in young patients with severe psychiatric disorders: a pilot study

Background and objectives

The present study aims to investigate the effect of the 4-F (Fit, Fun, Feel, and Food) group-based program on physical, clinical, and biological outcomes in young patients suffering from severe psychiatric disorders.

Methods

A pilot study with a naturalistic design was conducted to investigate the effect of a group-based intervention on young patients.

Results

A descriptive analysis revealed that out of the 61 outpatients initially enrolled in the program, with a mean age of 26.9 years old (±6.1, 60% men), 71% were overweight or obese. Paired T-tests for the difference between T0 and T1 were used to evaluate the evolution of the outcomes. The 24 patients who completed the full program showed no significant decrease in weight or body composition. Despite the limitations, the main findings of this study were the significant improvement in muscular endurance and coordination (from T0 (M = 13.65, SD = ±1.93) compared to T1 (M = 12.49, SD = ±1.81), [t(20) = 3.072, p < 0.05] and the general increase in mental well-being from baseline to the end of the program according to the type of psychopathology [F(3,10) = 4.25, p < .05]. A slight modification in eating behavior, with a tendency towards a decrease in TFEQ hunger levels, was also noticed. The ANCOVA showed no difference in outcomes between the groups based on diagnosis.

Conclusion

Despite its limitations and the small sample size, this pilot study provides valuable insights, demonstrating the feasibility of the program and its positive impact on physical well-being and improved mental health in young patients with psychiatric disorders, sedentary behavior, and unhealthy lifestyles. These encouraging results warrant further research in controlled, larger population samples to deepen our understanding of the potential effects of such interventions.

Research trends of exercise therapy of college students in depression from 2002 to 2022: a bibliometric analysis

Background

Depression is a serious psychological disorder that college students are experiencing. College students' depression problems, which can be caused by various factors, have been easily ignored and untreated. In recent years, exercise, as a low-cost and easily accessible method for treating depression, has attracted widespread attention. The purpose of this study is to use bibliometrics to explore the hotspots and trends in the field of exercise therapy of college students in depression from 2002 to 2022.

Methods

We retrieved relevant literature from the Web of Science (WoS), PubMed, and Scopus databases, and generated a ranking table to describe the core productivity in the field. We used VOSViewer software to generate network maps of authors, countries, co-cited journals, and co-occurring keywords to help us better understand the scientific collaboration patterns, potential disciplinary foundations, as well as research hotspots and trends in this field.

Results

From 2002 to 2022, a total of 1,397 articles related to exercise therapy of college students in depression were selected. The key findings of this study are as follows: (1) the number of publications has gradually increased, especially after 2019; (2) United States and its affiliated higher education institutions have made significant contributions to the development of this field; (3) there are multiple research groups in this field, but their connections are relatively limited; (4) the field is relatively interdisciplinary, primarily a convergence of behavioral science, public health, and psychology; (5) based on co-occurring keyword analysis, six main themes were summarized: health-promoting factors, body image, negative behaviors, increased stress, depression coping strategies, and diet.

Conclusion

Our study illustrates the research hotspots and trends for the research of exercise therapy of college students in depression, presents some challenges and new insights, and provides valuable information for further research.

Selecting Antidepressants Based on Medical History and Stress Mechanism

Purpose At present, clinicians typically prescribe antidepressants based on the widely accepted "serotonin hypothesis." This study explores an alternative mechanism, the stress mechanism, for selecting antidepressants based on patients' medical history. Methods This study investigated clinicians' prescribing patterns for the 15 most common antidepressants, including amitriptyline, bupropion, citalopram, desvenlafaxine, doxepin, duloxetine, escitalopram, fluoxetine, mirtazapine, nortriptyline, paroxetine, ropinirole, sertraline, trazodone, and Venlafaxine. The least absolute shrinkage and selection operator (LASSO) logistic regression was used to identify factors that affect the remission of depression symptoms after receiving an antidepressant. Results The study found that a wide range of factors influenced the propensity of clinicians to prescribe antidepressants, with the number of predictors ranging from 51 to 206 variables. The prevalence of prescribing an antidepressant ranged from 0.5% for doxepin to 24% for the combination of more than one antidepressant. The area under the receiver operating curves (AROC) ranged from 77.2% for venlafaxine to 90.5% for ropinirole, with an average AROC of 82% for predicting the propensity of medications. A variety of diagnoses and prior medications affected remission, in agreement that the central mechanism for the impact of medications on the brain is through stress reduction. For example, psychotherapy, whether done individually or in a group, whether done for a short or long time, and whether done with evaluation/assessment or not, had an impact on remission. Specifically, teenagers and octogenarians were less likely to benefit from bupropion, citalopram, escitalopram, fluoxetine, and sertraline compared to patients between 40 and 65 years old. The findings of this study suggest that considering a patient's medical history and individual characteristics is crucial for selecting the most effective antidepressant treatment. Conclusions Many studies have raised doubt about the serotonin hypothesis as the central mechanism for depression treatment. The identification of a wide range of predictors for prescribing antidepressants highlights the complexity of depression treatment and the need for individualized approaches that consider patients' comorbidities and previous treatments. The significant impact of comorbidities on the response to treatment makes it improbable that the mechanism of action of antidepressants is solely based on the serotonin hypothesis. It is hard to explain how comorbidities lead to the depletion of serotonin. These findings open up a variety of courses of action for the clinical treatment of depression, each addressing a different source of chronic stress in the brain. Overall, this study contributes to a better understanding of depression treatment and provides valuable insights for clinicians in selecting antidepressants based on patients' medical history.

Physical Fitness for Depression in Adolescents and Adults: A Meta-Analysis

Background

Depression has been recognized as one of the most significant factors affecting mental health status. For this reason, several efforts to prevent and reduce depression in all ages have been made in various domains to identify the relevant factors as well as the causes of depression. The objective of this meta-analysis was to examine the effect size between physical fitness and depression in adolescents and adults.

Methods

A systematic search for meta-analysis (2009-2020) was performed using PubMed, Scopus, Web of Science, and RISS, with key terms such as depression, depressive illness, and physical fitness or fitness. Overall, 19 out of 448 articles were included in the meta-analysis with strict inclusion criteria.

Results

The effect size is a medium between physical fitness and depression in adolescents and adults. Two fitness factors, namely cardiovascular endurance and muscle strength, are more relevant for alleviating depression in adolescents and adults, whereas agility was not related to depression. In particular, the cardiovascular fitness factor has an impact on almost all ages; however, muscular strength has less impact on depression in young adolescents, but has a great impact on older adults' depression.

Conclusion

The effect size in this study is a medium between physical fitness and depression in adolescents and adults. Thus, more longitudinal and clinical studies with larger sample sizes are needed to clarify the relationship between physical fitness and depression.

Effect of a Low-Carbohydrate Diet With or Without Exercise on Anxiety and Eating Behavior and Associated Changes in Cardiometabolic Health in Overweight Young Women

Background

The effectiveness of low-carbohydrate diets (LCDs) on weight loss and exercise for improving cardiometabolic fitness have been well documented in the literature, but the effects of LCDs and whether adding exercise to a LCD regime could additionally benefit mental health (e. g., by lowering the level of anxiety) and associated changes in eating behavior are less clear in overweight and obese populations. Therefore, this study aimed to investigate the effects of a 4-week LCD with or without exercise on anxiety and eating behavior, and to explore the associations between changes in the psychological state and physiological parameters (i.e., body composition, aerobic fitness, blood pressure, lipid profile, and metabolic hormones).

Methods

Seventy-four overweight Chinese women [age: 20.8 ± 3.0 years, body mass index (BMI): 25.3 ± 3.3 kg·m⁻²] completed the 4-week randomized controlled trial, which included a LCD group (i.e., ~50 g daily carbohydrate intake) with exercise training 5 days/week (LC-EXE, n = 26), a LCD group without exercise training (LC-CON, n = 25) and a control group that did not modify their habitual diets and physical activity (CON, n = 23). Levels of anxiety, eating behavior scores and physiological parameters (i.e., body weight, V̇O_2peak, blood pressure, fasting glucose, blood lipids, and serum metabolic hormones including insulin, C-peptide, leptin, and ghrelin) were measured before and after the intervention.

Results

There were significant reductions in anxiety levels in the LC-EXE compared with the LC-CON group, while no statistical changes were found in eating behaviors in any conditions after the 4-week intervention. Significant reduction in weight (~3.0 kg or 4%, p < 0.01) and decreases in insulin (~30% p < 0.01), C-peptide (~20% p < 0.01), and leptin (~40%, p < 0.01) were found in both LC-CON and LC-EXE groups, but adding exercise to a LCD regime generated no additional effects. There were significant improvements in V̇O_2peak (~15% p < 0.01) and anxiety (~25% p < 0.01) in the LC-EXE compared with the LC-CON group, while no statistical differences were found between CON and LC-CON treatments. Further analysis revealed a negative association (r = −0.32, p < 0.01) between changes in levels of anxiety and changes in V̇O_2peak in all participates, no other correlations were found between changes in psychological and physiological parameters.

Conclusion

Although the combination of a LCD and exercise may not induce additional reductions in body weight in overweight young females, exercise could be a useful add-on treatment along with a LCD to improve cardiometabolic health and lower anxiety levels.

Effects of exercise on symptoms of anxiety in primary care patients: A randomized controlled trial

BACKGROUND

There is a need for high-quality research regarding exercise interventions for persons with anxiety disorders. We investigate whether a 12-week exercise intervention, with different intensities, could reduce anxiety symptoms in patients with anxiety disorders.

METHODS

286 patients were recruited from primary care in Sweden. Severity of symptoms was self-assessed using the Beck Anxiety Inventory (BAI) and the Montgomery Åsberg Depression Rating Scale (MADRS-S). Participants were randomly assigned to one of two group exercise programs with cardiorespiratory and resistance training and one control/standard treatment non-exercise group, with 1:1:1 allocation.

RESULTS

Patients in both exercise groups showed larger improvements in both anxiety and depressive symptoms compared to the control group. No differences in effect sizes were found between the two groups. To study a clinically relevant improvement, BAI and MADRS-S were dichotomized with the mean change in the control group as reference. In adjusted models the odds ratio for improved symptoms of anxiety after low-intensity training was 3.62 (CI 1.34-9.76) and after moderate/high intensity 4.88 (CI 1.66-14.39), for depressive symptoms 4.96 (CI 1.81-13.6) and 4.36 (CI 1.57-12.08) respectively. There was a significant intensity trend for improvement in anxiety symptoms.

LIMITATIONS

The use of self-rating measures which bears the risk of an under- or overestimation of symptoms.

CONCLUSIONS

A 12-week group exercise program proved effective for patients with anxiety syndromes in primary care. These findings strengthen the view of physical exercise as an effective treatment and could be more frequently made available in clinical practice for persons with anxiety issues.

Change in cardiorespiratory fitness on self-rated health: prospective cohort study in 98 718 Swedish adults

Aim: To study how change in cardiorespiratory fitness over time is associated with the development of poor self-rated health in healthy Swedish adults, and whether this association varies with sex, age, body mass index and cardiorespiratory fitness at baseline. A secondary aim was to study the influence of other predictors of self-rated health. Methods: A total of 98,718 participants (45% women, mean age 42.2 years) with two assessments from occupational health service screenings between 1988 and 2019 (mean duration 4.3 years), with good self-rated health at baseline were included. Cardiorespiratory fitness was assessed as estimated maximal oxygen consumption using submaximal cycle testing. Change in cardiorespiratory fitness was expressed as percentage annual change. Poor self-rated health at follow-up was defined as percieving self-rated health as 'poor' or 'very poor'. Results: A large decrease in cardiorespiratory fitness (⩾-3%) was associated with a 34% higher risk of poor self-rated health compared to maintainers (-1 to +1%) after multi-adjustment including change in body mass index, back/neck pain, stress, exercise habits and sleep quality or sleep problems. The associations for decreasers were stronger with longer follow-up time (>10 years). Preserving, or changing to, risk level for body mass index, back/neck pain, stress, exercise and sleep quality/problems were associated with a higher risk of poor self-rated health. Conclusions: Preserving or increasing cardiorespiratory fitness is associated with a lower risk of poor self-rated health, independently of change in other health-related variables, which may act as a protection against future poor self-rated health. This is of high clinical value, and strategies for maintaining or improving cardiorespiratory fitness have the potential to influence both disease and mortality.

Associations between exercise, inflammation and symptom severity in those with mental health disorders

AIM

This study aimed to investigate the effects of 6-weeks of moderate intensity aerobic exercise on markers of inflammation and symptom severity in those undergoing management of a mental health disorder.

METHOD

Twenty six participants were allocated into two groups, those reporting as apparently healthy (AH, n = 13) or those undergoing the management of a mental health disorder (MI, n = 13). Following a baseline testing and familiarization session, participants commenced the 6-week aerobic training intervention, involving stationary cycling at 65% heart rate reserve for 35 min progressing to 70% for 40 min. Measures of aerobic fitness (VO_2peak), anthropometric variables, symptom questionnaires and venous blood were collect pre- and post-intervention. Venous blood was assessed for nod-like receptor pyrin containing-3, interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), IL-1β, C-reactive protein (CRP) and brain-derived neurotropic factor (BDNF).

RESULTS

There were no baseline differences between groups, however following the intervention the AH demonstrated lower TNF-α (p = 0.049) than the MI group. Within change was observed for the MI group with an increase in VO_2peak (p = 0.049) and declines in symptom severity (p = 0.00-0.005). Significant correlations between variables indicated a positive association between body fat, body fat percentage, CRP and symptom severity (p = 0.01-0.04). Conversely, symptom severity and CRP were inversely associated with VO_2peak values (p = 0.02-0.04).

CONCLUSION

Six-weeks of moderate intensity aerobic exercise increases VO_2peak and reduces symptom severity in those currently undergoing management of a mental health disorder. Further, there may be a physiological link between aerobic capacity, symptom severity, inflammation and adiposity, however greater exploration is required.

Aerobic exercise or stretching as add-on to inpatient treatment of depression: Similar antidepressant effects on depressive symptoms and larger effects on working memory for aerobic exercise alone

BACKGROUND

Aerobic exercise (AE) has positive effects on symptom severity and cognitive symptoms of depression. Since data on AE as add-on to inpatient treatment in depression is still scarce, we conducted this double-blind randomized controlled study.

METHODS

Patients aged between 18 and 60 years were recruited into the study if Hamilton Depression Rating Scale 17 (HDRS-17) score was >16. Participants were randomly assigned to either AE or basic stretching activities (control), which took place 3x/week for 6 weeks. Primary outcome was depression severity as assessed with the HDRS-17 and the Beck Depression Inventory (BDI). Further physiological and psychological variables and cognitive performance were assessed as secondary outcomes.

RESULTS

Forty-two patients were included in the analysis (exercise: n = 22; control: n = 20). Regardless of group allocation, we found a significant short-term time effect for symptom-severity (HDRS17: p<0.001, η²=0.70; BDI: p<0.001, η²=0.51), mental toughness (p<0.001, η²=0.32), physical self-description endurance score (p = 0.013, η²=0.16), cognitive flexibility (p = 0.013, η²=0.14), and body mass index (BMI) (p = 0.006, η²=0.19). Working memory showed a significant time by group interaction in favor of AE (p = 0.043, η²=0.10). Short-term effects on symptom severity, mental toughness and BMI remained stable across the 6-month follow-up period. Finally, self-reported physical activity increased significantly from baseline to follow-up (p = 0.014, η²=0.15).

LIMITATIONS

The sample-size is rather small. The control intervention might have been too active as to find a time by group interaction for symptom severity.

CONCLUSIONS

AE was associated with comparably large depression alleviation vs. stretching and with add-on benefits on working memory.

Effectiveness of a brief lifestyle intervention targeting mental health staff: analysis of physical fitness and activity in the Keeping Our Staff in Mind study

BACKGROUND

People with mental illness die on average 15 years less than the general population, primarily to cardiometabolic disease. Lifestyle interventions are effective in reducing cardiometabolic risk but are not routinely provided to mental health consumers. Lifestyle interventions targeting mental health staff may be beneficial in changing culture surrounding physical health and subsequently improving consumer outcomes. This study examines exercise and fitness outcomes of a targeted lifestyle intervention directed at Australian mental health staff.

METHODS

A pragmatic single-arm intervention study was conducted within an Australian public mental health service. Mental health staff were provided a five-session individualised lifestyle intervention (incorporating exercise and nutritional counselling) over 5 weeks. Two waves of the programme were delivered between 2015 and 2016. This paper examines the exercise and fitness outcomes of the second wave of the study. Participants were assessed at baseline and at a 16-week follow-up. The primary exercise outcome was a measurement of cardiorespiratory fitness. Secondary outcomes included self-reported physical activity and a measurement of handgrip strength.

RESULTS

A total of 106 staff participated in this component of the study. Cardiorespiratory fitness increased significantly from baseline to follow-up (p<0.001). Significant improvements to physical activity occurred with decreases in sedentary time (p<0.0005) and increases in moderate-to-vigorous physical activity (p<0.005).

CONCLUSION

Lifestyle interventions incorporating exercise counselling may improve the physical health of mental health staff. Such strategies may be effective in improving culture surrounding physical health and/or increasing the effectiveness of lifestyle interventions targeting mental health consumers.

Impact of unhealthy lifestyle on cardiorespiratory fitness and heart rate recovery of medical science students

Background

Medical science students represent valuable labour resources for better future medicine and medical technology. However, little attention was given to the health and well-being of these early career medical science professionals. The aim of this study is to investigate the impact of lifestyle components on cardiorespiratory fitness and heart rate recovery measured after moderate exercise in this population.

Methods

Volunteers without documented medical condition were recruited randomly and continuously from the first-year medical science students during 2011–2014 at the University of Surrey, UK. Demographics and lifestyle components (the levels of smoking, alcohol intake, exercise, weekend outdoor activity and screen-time, daily sleep period, and self-assessment of fitness) were gathered through pre-exercise questionnaire. Cardiorespiratory fitness (VO₂max) and heart rate recovery were determined using Åstrand–Rhyming submaximal cycle ergometry test. Data were analysed using SPSS version 25.

Results

Among 614 volunteers, 124 had completed both lifestyle questionnaire and the fitness test and were included for this study. Within 124 participants (20.6 ± 4 years), 46.8% were male and 53.2% were female, 11.3% were overweight and 8.9% were underweight, 8.9% were current smokers and 33.1% consumed alcohol beyond the UK recommendation. There were 34.7% of participants admitted to have < 3 h/week of moderate physical activity assessed according to UK Government National Physical Activity Guidelines and physically not fit (feeling tiredness). Fitness test showed that VO₂max distribution was inversely associated with heart rate recovery at 3 min and both values were significantly correlated with the levels of exercise, self-assessed fitness and BMI. Participants who had < 3 h/week exercise, or felt not fit or were overweight had significantly lower VO₂max and heart rate recovery than their peers.

Conclusion

One in three new medical science students were physically inactive along with compromised cardiorespiratory fitness and heart rate recovery, which put them at risk of cardiometabolic diseases. Promoting healthy lifestyle at the beginning of career is crucial in keeping medical science professionals healthy.

The association between physical fitness and mental health in Norwegian adolescents

BACKGROUND

Studies indicate that health-related components of physical fitness are associated with mental health outcomes. However, research is scarce concerning this relationship in young adolescents in general and non-existent in Norwegian populations specifically. The aim of the study was to examine whether body composition, muscular strength and cardiorespiratory fitness were associated with self-reported mental health in Norwegian adolescents.

METHODS

Adolescents from four regions of Norway (n = 1486; mean age = 13.9; girls = 50.6%) participated. Self-reported mental health (psychological difficulties) was measured by completing the Strengths and Difficulties Questionnaire. Cardiorespiratory fitness was assessed with an intermittent running test; muscular strength was assessed by measuring handgrip strength, standing broad jump and sit-ups; and body composition was assessed by calculating body mass index from weight and height. Linear mixed effects models were conducted to assess the associations between the health-related components of physical fitness and psychological difficulties. School clusters were included as random effects and all models were controlled for sex, socioeconomic status and birthplace (domestic or foreign).

RESULTS

Body composition was not associated with psychological difficulties. Muscular strength was independently associated with psychological difficulties, but when all independent variables were entered in the fully adjusted model, only cardiorespiratory fitness was associated with psychological difficulties.

CONCLUSIONS

There was a small but significant inverse association between cardiorespiratory fitness and levels of psychological difficulties in Norwegian adolescents. The results suggest that muscular strength is not associated with psychological difficulties in adolescents, when controlling for cardiorespiratory fitness. Future research should focus on the prospective association between physical fitness components and mental health outcomes in adolescents.

TRIAL REGISTRATION

The study is registered in ClinicalTrials.gov ID nr: NCT03817047. Retrospectively registered January 25, 2019.

Exercise and Schizophrenia

Schizophrenia is a psychiatric disorder characterized by distortions of thinking and perception, with no strictly pathognomonic symptoms that can be divided into positive, negative, and cognitive symptom domains. People with schizophrenia have, between others, a reduced life expectancy and cardiorespiratory and muscular fitness and increased risk of cardiovascular disease, metabolic syndrome, obesity, hypertension, and hyperlipidemia compared to the general population. Furthermore, the economic burden of mental disorders including schizophrenia is evident and it is expected to increase to more than double by 2030. Therefore, reducing the growing burden of mental disorders such as schizophrenia should be a health priority. Improved prevention and treatment are two key factors that may reduce the burden of schizophrenia. Pharmacological- and psychotherapy-based interventions have been traditionally considered for treating schizophrenia disorders; however, there is an increasing amount of scientific evidence confirming that physical activity and physical exercise should be highly considered in prevention and treatment of schizophrenia disorders. In this chapter, we aim to summarize and discuss the research progress of physical activity and exercise in prevention and treatment of schizophrenia disorder. Specifically, we summarized and discussed the research progress of the prognostic use of physical activity for incident schizophrenia; the importance of other outcomes typically improved by physical activity/exercise such as obesity and fitness (cardiorespiratory and muscular fitness) for future schizophrenia; the research progress of the evidence of the benefits of exercise in people with schizophrenia disorders differentiating between effects of exercise on varied health outcomes, cognitive functioning, and cardiorespiratory fitness; and finally the clinical practice recommendations.

Exercise and Anxiety

Anxiety disorders are a group of highly prevalent mental health conditions that can have a debilitating impact on daily functioning and well-being. They can co-occur with other mental health disorders, such as depression. People with anxiety disorders are also at an elevated risk of cardiovascular disease and premature mortality. Physical activity appears to be protective against anxiety disorders in clinical and nonclinical populations. Exercise, a subset of physical activity, has been shown to significantly reduce the symptoms of anxiety. The mechanisms through which exercise produces these effects are likely to involve a combination of biological and psychological factors. Physical activity may also be useful in reducing the symptoms of comorbid mental health conditions and the risk of physical health complications over time. Promoting physical activity could be a method of preventing or treating anxiety disorders with a wide range of benefits. However, further research will be necessary to address important gaps in the literature before these approaches can be fully implemented in mental health services.

Physical activity and depression: Towards understanding the antidepressant mechanisms of physical activity

Physical activity can treat and prevent depressive symptoms, but its antidepressant mechanisms are yet to be established. In this review, we comprehensively assess key biological and psychosocial mechanisms through which physical activity exerts antidepressant effects, with a particular focus on exercise. Exercise, a subset of physical activity, influences a range of biological and psychosocial processes also implicated in the pathophysiology of depression. We focus on the capacity for exercise to elicit changes in neuroplasticity, inflammation, oxidative stress, the endocrine system, self-esteem, social support and self-efficacy. We also discuss how a better understanding of these mechanisms can inform the way we design and implement exercise-based interventions to maximise their antidepressant effects on an individual basis. We conclude by presenting a conceptual framework of the key biological and psychosocial mechanisms underlying the relationship between physical activity and depressive symptoms, and the moderators and confounders that may influence it.

The association between cardiorespiratory fitness and the incidence of common mental health disorders: A systematic review and meta-analysis

BACKGROUND

Physical activity is associated with a lower incidence of common mental health disorder, but less is known about the impact of cardiorespiratory fitness (CRF).

METHODS

In this review, we systematically evaluated the relationship between CRF and the incidence of common mental health disorders in prospective cohort studies. We systematically searched six major electronic databases from inception to 23rd of May 2019. We assessed study quality using the Newcastle-Ottawa scale.

RESULTS

We were able to pool the hazard ratios (HRs) and 95% confidence intervals (CIs) of four studies including at least 27,733,154 person-years of data. We found that low CRF (HR = 1.47, [95% CI 1.23 - 1.76] p < 0.001 I2 = 85.1) and medium CRF (HR = 1.23, [95% CI 1.09 - 1.38] p < 0.001 I2 = 87.20) CRF are associated with a 47% and 23% greater risk of a common mental health disorders respectively, compared with high CRF. We found evidence to suggest a dose-response relationship between CRF and the risk of common mental health disorders.

LIMITATIONS

We were only able to identify a small number of eligible studies from our search and heterogeneity was substantial in the subsequent meta-analysis.

CONCLUSIONS

Our findings indicate that there is a longitudinal association between CRF levels and the risk of a common mental health disorder. CRF levels could be useful for identifying and preventing common mental health disorders at a population-level.

Cross-sectional and longitudinal association of non-exercise estimated cardiorespiratory fitness with depression and anxiety in the general population: The HUNT study

BACKGROUND

Cardiorespiratory fitness may help to prevent depression and anxiety. A paucity of literature has considered the relationship between cardiorespiratory fitness (CRF) and the incidence of depression and anxiety. The objective of this study was to investigate cross-sectional and longitudinal associations of estimated cardiorespiratory fitness (CRF) with depression and anxiety.

METHODS

This study included middle-aged and older participants from the second (HUNT 2, 1995-1997) and third (HUNT3, 2006-2008) survery of the Nord-Trøndelag Health Study (HUNT). Baseline non-exercise estimated CRF (eCRF) was determined using standardized algorithms. Depression and anxiety were measured using the Hospital Anxiety and Depression Scale. Logistic regression models were used to evaluate the cross-sectional and longitudinal associations between eCRF and depression and anxiety.

RESULTS

In cross-sectional adjusted analysis including those who participated in HUNT2 (n = 26,615 mean age 55.7 years), those with medium and high level of eCRF had 21% (OR, 0.79; 95% CI, 0.71-0.89) and 26% (OR, 0.74; 95% CI, 0.66-0.83) lower odds of depression compared to those with low eCRF level, respectively. Longitudinal analysis including those who participated in both HUNT2 and HUNT3 (n = 14,020 mean age 52.2 years) found that medium and level of eCRF was associated with 22% (OR, 0.78; 95% CI, 0.64-0.96) and 19% (OR, 0.81; 95% CI, 0.66-0.99) lower odds of depression compared to those with low eCRF level, respectively. CRF was not associated with anxiety, either cross-sectionally or longitudinally.

CONCLUSION

Our data suggest that a medium and high level of eCRF during late middle age is cross-sectionally and prospectively associated with lower odds of depression. However, our data do not support that eCRF is associated with anxiety. Further studies are warranted to conclude a causal relationship between eCRF and depression.

Physical exercise and body mass index as correlates of major depressive disorder in community-dwelling adults: Results from the PISMA-ep study

BACKGROUND

Major Depressive Disorder (MDD) is one of the most prevalent and disabling mental disorders. Sedentarism and obesity are recognized risk factors for MDD. Physical exercise has shown beneficial effects on mental health and there is an increasing awareness of its potential as a therapeutic and preventive tool for depression. No epidemiological studies have explored the role of physical activity and obesity as potential correlates of MDD in the Spanish population. The aim of this study was to explore whether MDD was associated with two strongly linked variables: physical exercise and body mass index.

METHODS

The PISMA-ep is a cross-sectional community-based study carried out in Andalusia, southern Spain. Main outcome was current prevalence of MDD, measured through face-to-face interviews using the Mini-International Neuropsychiatric Interview (MINI). Independent variables explored were physical exercise and its intensity, Body Mass Index (BMI), BMI categories (underweight, normal weight, overweight and obesity), hip and waist circumferences, general health status measured with the SF12 questionnaire, and sociodemographic factors.

RESULTS

Physical exercise was inversely associated with MDD, acting as a protective factor. Higher intensity of exercise strengthened this association. Four variables were independently associated with MDD in the multivariate association model: female sex, physical exercise, general health status and BMI.

CONCLUSION

MDD was associated with poorer health status, higher BMI and reduced physical activity. Physical exercise should be considered as a potential intervention for the treatment and prevention of MDD in clinical and public health settings.