Treating depression and depression-like behavior with physical activity: an immune perspective

The increasing burden of major depressive disorder makes the search for an extended understanding of etiology, and for the development of additional treatments highly significant. Biological factors may be useful biomarkers for treatment with physical activity (PA), and neurobiological effects of PA may herald new therapeutic development in the future. This paper provides a thorough and up-to-date review of studies examining the neuroimmunomodulatory effects of PA on the brain in depression and depression-like behaviors. From a neuroimmune perspective, evidence suggests PA does enhance the beneficial and reduce the detrimental effects of the neuroimmune system. PA appears to increase the following factors: interleukin (IL)-10, IL-6 (acutely), macrophage migration inhibitory factor, central nervous system-specific autoreactive CD4+ T cells, M2 microglia, quiescent astrocytes, CX3CL1, and insulin-like growth factor-1. On the other hand, PA appears to reduce detrimental neuroimmune factors such as: Th1/Th2 balance, pro-inflammatory cytokines, C-reactive protein, M1 microglia, and reactive astrocytes. The effect of other mechanisms is unknown, such as: CD4+CD25+ T regulatory cells (T regs), CD200, chemokines, miRNA, M2-type blood-derived macrophages, and tumor necrosis factor (TNF)-α [via receptor 2 (R2)]. The beneficial effects of PA are likely to occur centrally and peripherally (e.g., in visceral fat reduction). The investigation of the neuroimmune effects of PA on depression and depression-like behavior is a rapidly developing and important field.

Psychosocial stress and cardiovascular disease risk: the role of physical activity

Chronic stress and depression are associated with increased risk of cardiovascular disease and poorer prognosis, and physical (in)activity may be a key underlying biobehavioral mechanism. Physical activity has antidepressant effects, and physically fitter, more active individuals seem to be more biologically resilient to psychosocial stressors. This article will present data from a series of population cohort studies and laboratory-based psychophysiological studies to explore the role of physical activity as a protective factor against the effects of psychosocial stress on cardiovascular disease. These mechanisms may improve the treatment and prevention of stress-related illnesses and, thus, has important implications for public health and clinical care of high-risk patients.

Cancer caregivers' perceptions of an exercise and nutrition program

PURPOSE

Little research has addressed exercise and nutrition-based interventions for cancer caregivers. This study explored cancer caregivers' perceptions of participating in a structured exercise and nutrition program alongside cancer survivors for whom they provided care.

METHODS

In-depth, semi-structured interviews were conducted by one interviewer with 12 cancer caregivers about their experiences participating in a structured, 12-week exercise and nutrition program designed for cancer survivors and caregivers to complete concurrently. Interviews were conducted until data saturation was reached.

RESULTS

Inductive content analysis from individual interviews indicated three separate, but interrelated, themes: (1) the program was a positive mechanism through which caregivers shared and supported the cancer journey concurrently with survivors, (2) the program led to perceived physical and psychological benefits for both caregivers and survivors, and (3) participants perceived that participation in the program led to feeling increased social support in their caregiving duties.

CONCLUSIONS

Findings from this study suggest that participating in an exercise- and nutrition-based intervention is viewed positively by caregivers and that the outcomes are seen as beneficial to both caregivers and survivors. Interventions that address the health needs of both members of the caregiver-survivor dyad should continue to be encouraged by allied health professionals.

Complementary medicine, exercise, meditation, diet, and lifestyle modification for anxiety disorders: a review of current evidence

Use of complementary medicines and therapies (CAM) and modification of lifestyle factors such as physical activity, exercise, and diet are being increasingly considered as potential therapeutic options for anxiety disorders. The objective of this metareview was to examine evidence across a broad range of CAM and lifestyle interventions in the treatment of anxiety disorders. In early 2012 we conducted a literature search of PubMed, Scopus, CINAHL, Web of Science, PsycInfo, and the Cochrane Library, for key studies, systematic reviews, and metaanalyses in the area. Our paper found that in respect to treatment of generalized anxiety or specific disorders, CAM evidence revealed current support for the herbal medicine Kava. One isolated study shows benefit for naturopathic medicine, whereas acupuncture, yoga, and Tai chi have tentative supportive evidence, which is hampered by overall poor methodology. The breadth of evidence does not support homeopathy for treating anxiety. Strong support exists for lifestyle modifications including adoption of moderate exercise and mindfulness meditation, whereas dietary improvement, avoidance of caffeine, alcohol, and nicotine offer encouraging preliminary data. In conclusion, certain lifestyle modifications and some CAMs may provide a beneficial role in the treatment of anxiety disorders.

Exercise for depression

BACKGROUND

Depression is a common and important cause of morbidity and mortality worldwide. Depression is commonly treated with antidepressants and/or psychotherapy, but some people may prefer alternative approaches such as exercise. There are a number of theoretical reasons why exercise may improve depression. This is an update of an earlier review first published in 2009.

OBJECTIVES

To determine the effectiveness of exercise in the treatment of depression. Our secondary outcomes included drop-outs from exercise and control groups, costs, quality of life and adverse events.

SEARCH METHODS

We searched the Cochrane Depression, Anxiety and Neurosis (CCDAN) Review Group's Specialised Register (CCDANCTR), CENTRAL, MEDLINE, EMBASE, Sports Discus and PsycINFO for eligible studies (to February 2010). We also searched www.controlled-trials.com in November 2010. The CCDAN Group searched its Specialised Register in June 2011 and potentially eligible trials were listed as 'awaiting assessment'.

SELECTION CRITERIA

Randomised controlled trials in which exercise was compared to standard treatment, no treatment or a placebo treatment in adults (aged 18 and over) with depression, as defined by trial authors. We excluded trials of postnatal depression.

DATA COLLECTION AND ANALYSIS

For this update, two review authors extracted data on outcomes at the end of the trial. We used these data to calculate effect sizes for each trial using Hedges' g method and a standardised mean difference (SMD) for the overall pooled effect, using a random-effects model. Where trials used a number of different tools to assess depression, we included the main outcome measure only in the meta-analysis. We systematically extracted data on adverse effects and two authors performed the 'Risk of bias' assessments.

MAIN RESULTS

Thirty-two trials (1858 participants) fulfilled our inclusion criteria, of which 30 provided data for meta-analyses. Randomisation was adequately concealed in 11 studies, 12 used intention-to-treat analyses and nine used blinded outcome assessors. For the 28 trials (1101 participants) comparing exercise with no treatment or a control intervention, at post-treatment analysis the pooled SMD was -0.67 (95% confidence interval (CI) -0.90 to -0.43), indicating a moderate clinical effect. However, when we included only the four trials (326 participants) with adequate allocation concealment, intention-to-treat analysis and blinded outcome assessment, the pooled SMD was -0.31 (95% CI -0.63 to 0.01) indicating a small effect in favour of exercise. There was no difference in drop-outs between exercise and control groups. Pooled data from the seven trials (373 participants) that provided long-term follow-up data also found a small effect in favour of exercise (SMD -0.39, 95% CI -0.69 to -0.09). Of the six trials comparing exercise with cognitive behavioural therapy (152 participants), the effect of exercise was not significantly different from that of cognitive therapy. There were insufficient data to determine risks, costs and quality of life.Five potentially eligible studies identified by the search of the CCDAN Specialised Register in 2011 are listed as 'awaiting classification' and will be included in the next update of this review.

AUTHORS' CONCLUSIONS

Exercise seems to improve depressive symptoms in people with a diagnosis of depression when compared with no treatment or control intervention, however since analyses of methodologically robust trials show a much smaller effect in favour of exercise, some caution is required in interpreting these results.

[Exercise and psychological well-being]

Research on the association between physical activity and mental health addresses the beneficial effects of physical activity on emotional and cognitive functioning. With regard to emotional functioning, most studies focus on the influence of physical activity on depressive symptoms or affective disorders. These studies show that the beneficial effects of aerobic exercise and pharmacotherapy on depressive symptoms seem to be comparable and discuss a variety of neurobiological mechanisms that improve symptoms. The positive effects of physical activity on anxious mood and anxiety disorders are also well documented. Desensitization to physiological changes, improved self-esteem, and self-efficacy seem to play an important part. However, aerobic exercise does not improve mental health in every case, as seen for instance in over-trained athletes. Research on the relationship between physical activity and cognitive functioning reveals that physical activity can prevent the age-related cognitive decline and can delay the onset of dementia. Physical activity has beneficial effects not only on adults but also on children's and adolescents' mental health and cognitive performance, particularly on their executive functions that are still developing throughout adolescence. Finally, physical activity also affects the endocrine stress-regulation system: trained people reveal stronger reactivity and quicker regeneration when faced with stressful events.

Exercise prescription for hospitalized people with chronic obstructive pulmonary disease and comorbidities: a synthesis of systematic reviews

INTRODUCTION

The prescription of physical activity for hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) can be complicated by the presence of comorbidities. The current research aimed to synthesize the relevant literature on the benefits of exercise for people with multimorbidities who experience an AECOPD, and ask: What are the parameters and outcomes of exercise in AECOPD and in conditions that are common comorbidities as reported by systematic reviews (SRs)?

METHODS

An SR was performed using the Cochrane Collaboration protocol. Nine electronic databases were searched up to July 2011. Articles were included if they (1) described participants with AECOPD, chronic obstructive pulmonary disease (COPD), or one of eleven common comorbidities, (2) were an SR, (3) examined aerobic training (AT), resistance training (RT), balance training (BT), or a combination thereof, (4) included at least one outcome of fitness, and (5) compared exercise training versus control/sham.

RESULTS

This synthesis examined 58 SRs of exercise training in people with AECOPD, COPD, or eleven chronic conditions commonly associated with COPD. Meta-analyses of endurance (aerobic or exercise capacity, 6-minute walk distance--6MWD) were shown to significantly improve in most conditions (except osteoarthritis, osteoporosis, and depression), whereas strength was shown to improve in five of the 13 conditions searched: COPD, older adults, heart failure, ischemic heart disease, and diabetes. Several studies of different conditions also reported improvements in quality of life, function, and control or prevention outcomes. Meta-analyses also demonstrate that exercise training decreases the risk of mortality in older adults, and those with COPD or ischemic heart disease. The most common types of training were AT and RT. BT and functional training were commonly applied in older adults. The quality of the SRs for most conditions was moderate to excellent (>65%) as evaluated by AMSTAR scores.

CONCLUSION

In summary, this synthesis showed evidence of significant benefits from exercise training in AECOPD, COPD, and conditions that are common comorbidities. A broader approach to exercise and activity prescription in pulmonary rehabilitation may induce therapeutic benefits to ameliorate clinical sequelae associated with AECOPD and comorbidities such as the inclusion of BT and functional training.

Aerobic exercise training during pregnancy reduces depressive symptoms in nulliparous women: a randomised trial

QUESTION

Does supervised aerobic exercise during pregnancy reduce depressive symptoms in nulliparous women?

DESIGN

Randomised trial with concealed allocation, blinded assessors, and intention-to-treat analysis.

PARTICIPANTS

80 nulliparous, pregnant women attending for prenatal care at one of three tertiary hospitals in Cali, Colombia.

INTERVENTION

The experimental group completed a 3-month supervised exercise program, commencing at 16 to 20 weeks of gestation. Each session included walking (10 min), aerobic exercise (30 min), stretching (10 min), and relaxation (10 min). The control group continued usual activities and performed no specific exercise.

OUTCOME MEASURES

The primary outcome was symptoms of depression assessed by the Center for Epidemiological Studies Depression Scale (CES-D) at baseline and immediately after the 3-month intervention.

RESULTS

74 women completed the study. After the 3-month intervention, the experimental group reduced their depressive symptoms on the CES-D questionnaire by 4 points (95% CI 1 to 7) more than the control group.

CONCLUSIONS

A supervised 3-month program of primarily aerobic exercise during pregnancy reduces depressive symptoms.

TRIAL REGISTRATION

NCT00872365.

Sportaktivität als Stresspuffer

Zusammenfassung: Die Rolle des Sports als Strategie der Stressregulation ist noch wenig systematisch erforscht. Im vorliegenden Beitrag wird die sog. „Stresspuffer-Hypothese der Sportaktivität“ genauer geprüft. Sie besagt, dass Sportaktivität die negativen Auswirkungen von Stress auf die Gesundheit „abzupuffern“ vermag. Bis heute ist diese Hypothese noch nicht überzeugend empirisch belegt, vor allem mangelt es an längsschnittlicher und experimenteller Evidenz. In der vorliegenden Studie wird die Stresspuffer-Hypothese sowohl quer- als auch längsschnittlich überprüft: N = 427 Angestellte machten an zwei Messzeitpunkten im Abstand von zehn Monaten Angaben zu ihrer seelischen Gesundheit, ihrem arbeitsbedingten Stresserleben und ihrer Sportaktivität. Die Ergebnisse bestätigen den Stresspuffereffekt auf der Ebene der Querschnittsanalysen – bei Betrachtung des aktuellen Stresserlebens und des aktuellen Sporttreibens – nur teilweise, auf der Ebene der Längsschnittanalysen – bei Betrachtung des chronischen Stresserlebens und des chronischen Sporttreibens – dagegen in vollem Umfang. Die Befunde deuten darauf hin, dass das habituelle Sportverhalten insbesondere bei zeitlich andauernden Stressbedingungen seine gesundheitsprotektive Wirkung zu entfalten vermag.

Effect of running therapy on depression (EFFORT-D). Design of a randomised controlled trial in adult patients [ISRCTN 1894]

BACKGROUND

The societal and personal burden of depressive illness is considerable. Despite the developments in treatment strategies, the effectiveness of both medication and psychotherapy is not ideal. Physical activity, including exercise, is a relatively cheap and non-harmful lifestyle intervention which lacks the side-effects of medication and does not require the introspective ability necessary for most psychotherapies. Several cohort studies and randomised controlled trials (RCTs) have been performed to establish the effect of physical activity on prevention and remission of depressive illness. However, recent meta-analysis's of all RCTs in this area showed conflicting results. The objective of the present article is to describe the design of a RCT examining the effect of exercise on depressive patients.

METHODS/DESIGN

The EFFect Of Running Therapy on Depression in adults (EFFORT-D) is a RCT, studying the effectiveness of exercise therapy (running therapy (RT) or Nordic walking (NW)) on depression in adults, in addition to usual care. The study population consists of patients with depressive disorder, Hamilton Rating Scale for Depression (HRSD) ≥ 14, recruited from specialised mental health care. The experimental group receives the exercise intervention besides treatment as usual, the control group receives treatment as usual. The intervention program is a group-based, 1 h session, two times a week for 6 months and of increasing intensity. The control group only performs low intensive non-aerobic exercises. Measurements are performed at inclusion and at 3,6 and 12 months.Primary outcome measure is reduction in depressive symptoms measured by the HRSD. Cardio-respiratory fitness is measured using a sub maximal cycling test, biometric information is gathered and blood samples are collected for metabolic parameters. Also, co-morbidity with pain, anxiety and personality traits is studied, as well as quality of life and cost-effectiveness.

DISCUSSION

Exercise in depression can be used as a standalone or as an add-on intervention. In specialised mental health care, chronic forms of depression, co-morbid anxiety or physical complaints and treatment resistance are common. An add-on strategy therefore seems the best choice. This is the first high quality large trial into the effectiveness of exercise as an add-on treatment for depression in adult patients in specialised mental health care.

TRIAL REGISTRATION

Netherlands Trial Register (NTR): NTR1894.

Exercise as an adjunct treatment for opiate agonist treatment: review of the current research and implementation strategies

Opiate dependence is a significant public health concern linked to poor quality of life, comorbid psychiatric disorders, and high costs to society. Current opiate agonist treatments are an effective but limited intervention. Adjunctive interventions could improve and augment opiate agonist treatment outcomes, including drug abstinence, quality of life, and physical health. This article reviews exercise as an adjunctive intervention for opiate agonist treatment, especially in regards to improving mood and overall quality of life, while reducing other substance use. Poor adherence and dropout frequently prevent many individuals from garnering the many physical and mental health benefits of exercise. Strategies for implementing an exercise intervention, including safety considerations, are discussed.

Physical activity, stress reduction, and mood: insight into immunological mechanisms

Psychosocial factors, such as chronic mental stress and mood, are recognized as an important predictor of longevity and wellbeing. In particular, depression is independently associated with cardiovascular disease and all-cause mortality, and is often comorbid with chronic diseases that can worsen their associated health outcomes. Regular exercise is thought to be associated with stress reduction and better mood, which may partly mediate associations between depression, stress, and health outcomes. The underlying mechanisms for the positive effects of exercise on wellbeing remain poorly understood. In this overview we examine epidemiological evidence for an association between physical activity and mental health. We then describe the exercise withdrawal paradigm as an experimental protocol to study mechanisms linking exercise, mood, and stress. In particular we will discuss the potential role of the inflammatory response as a central mechanism.

Physical activity induces depression-like behavior in intact male rats

Testosterone affects behavior. Whether regular physical training does influence these effects is unknown. The assumption that testosterone induces muscular hypertrophy if combined with physical training has not been confirmed experimentally. The aim of this study was to evaluate whether activity and/or testosterone treatment affects depression-like behavior and to observe the effects of activity and testosterone on muscle fiber diameter. Forty-three male rats were divided into 4 groups: two groups (TST act and TST lazy) were treated with testosterone (5mg/kg) and two groups were used as control (CTRL act and CTRL lazy). Two of the groups (CTRL act and TST act) underwent 2weeks of exercise. The forced swim test was used as a test of depression-like behavior. Sex steroids were measured and the diameter of skeletal muscle fibers was evaluated. Testosterone was significantly higher in both testosterone-treated groups (p<0.001). Physically active groups had higher immobility times in the forced swim test than inactive groups. Groups CTRL act and TST lazy showed significantly larger diameter of muscle fibers in comparison to the TST act group. Our results suggest that physical activity induces depression-like behavior in rats. Controversial antagonistic effects of testosterone and physical activity on muscle fiber diameter were found.

Exercise effects on depressive symptoms in cancer survivors: a systematic review and meta-analysis

BACKGROUND

Depression is a distressing side effect of cancer and its treatment. In the general population, exercise is an effective antidepressant.

OBJECTIVE

We conducted a systematic review and meta-analysis to determine the antidepressant effect of exercise in cancer survivors.

DATA SOURCES

In May 2011, we searched MEDLINE, PsycInfo, EMBASE, CINAHL, CDSR, CENTRAL, AMED, Biosis Previews, and Sport Discus and citations from relevant articles and reviews.

STUDY ELIGIBILITY CRITERIA

We included randomized controlled trials (RCT) comparing exercise interventions with usual care in cancer survivors, using a self-report inventory or clinician rating to assess depressive symptoms, and reporting symptoms pre- and postintervention.

STUDY APPRAISAL

Around 7,042 study titles were identified and screened, with 15 RCTs included.

SYNTHESIS METHODS

Effect sizes (ES) were reported as mean change scores. The Q test was conducted to evaluate heterogeneity of ES. Potential moderator variables were evaluated with examination of scatter plots and Wilcoxon rank-sum or Kruskal-Wallis tests.

RESULTS

The overall ES, under a random-effects model, was -0.22 (confidence interval, -0.43 to -0.09; P = 0.04). Significant moderating variables (ps < 0.05) were exercise location, exercise supervision, and exercise duration.

LIMITATIONS

Only one study identified depression as the primary endpoint.

CONCLUSIONS

Exercise has modest positive effects on depressive symptoms with larger effects for programs that were supervised or partially supervised, not conducted at home, and at least 30 minutes in duration.

IMPACT

Our results complement other studies showing that exercise is associated with reduced pain and fatigue and with improvements in quality of life among cancer survivors.

American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise

The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

Exercise and severe depression: preliminary results of an add-on study

BACKGROUND

Physical exercise has been extensively researched as a therapeutic option for treatment of major depression.

METHODS

In a randomized controlled trial, we analyze the effects of aerobic physical exercise as an add-on strategy for treatment of severe depressed inpatients. The exercise has a "Dose" of 16.5 kcal/kg/week, three times a week during all the hospitalization.

RESULTS

Our preliminary results show that there is no significant difference in scores of Hamilton in the second week between groups (Mean[SD]=8.2[5.96] × 11.18[5.03], p=0.192). However, there is a significant reduction in Hamilton scores of patients in exercise group at discharge (Mean[SD]=5.93[4.46] × 9.45[3.56], p=0.041). Regarding Quality of Life (QoL), no significant difference were found between groups in the second week in physical domain (Mean[SD]=56.98[8.96] × 54.54[9.18], p=0.511) and psychological domain (Mean[SD]=50.88[13.88] × 42.04[12.42], p=0.106). However, there is a significant difference in psychological domain (Mean[SD]=55.88[9.92] v 41.66[13.04], p=0.004) and a trend but no statistical significance in the physical (Mean[SD]=58.80[9.14] × 52.12[8.70], p=0.07) at discharge.

LIMITATIONS

Many patients receive different treatment strategies, like ECT (1 patient at exercise group × 3 at control group). Other limitation is the small number of participants included until this moment.

CONCLUSION

Our preliminary results suggest that physical exercise could be a feasible and effective add-on strategy for treatment of severe depressed inpatients, improving their depressive symptoms and QoL.

Stimulant reduction intervention using dosed exercise (STRIDE) - CTN 0037: study protocol for a randomized controlled trial

Background

There is a need for novel approaches to the treatment of stimulant abuse and dependence. Clinical data examining the use of exercise as a treatment for the abuse of nicotine, alcohol, and other substances suggest that exercise may be a beneficial treatment for stimulant abuse, with direct effects on decreased use and craving. In addition, exercise has the potential to improve other health domains that may be adversely affected by stimulant use or its treatment, such as sleep disturbance, cognitive function, mood, weight gain, quality of life, and anhedonia, since it has been shown to improve many of these domains in a number of other clinical disorders. Furthermore, neurobiological evidence provides plausible mechanisms by which exercise could positively affect treatment outcomes. The current manuscript presents the rationale, design considerations, and study design of the National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) CTN-0037 Stimulant Reduction Intervention using Dosed Exercise (STRIDE) study.

Methods/Design

STRIDE is a multisite randomized clinical trial that compares exercise to health education as potential treatments for stimulant abuse or dependence. This study will evaluate individuals diagnosed with stimulant abuse or dependence who are receiving treatment in a residential setting. Three hundred and thirty eligible and interested participants who provide informed consent will be randomized to one of two treatment arms: Vigorous Intensity High Dose Exercise Augmentation (DEI) or Health Education Intervention Augmentation (HEI). Both groups will receive TAU (i.e., usual care). The treatment arms are structured such that the quantity of visits is similar to allow for equivalent contact between groups. In both arms, participants will begin with supervised sessions 3 times per week during the 12-week acute phase of the study. Supervised sessions will be conducted as one-on-one (i.e., individual) sessions, although other participants may be exercising at the same time. Following the 12-week acute phase, participants will begin a 6-month continuation phase during which time they will attend one weekly supervised DEI or HEI session.

Clinical Trials Registry

ClinicalTrials.gov, NCT01141608

http://clinicaltrials.gov/ct2/show/NCT01141608?term=Stimulant+Reduction+Intervention+using+Dosed+Exercise&rank=1

Eating disorders and exercise: a structural equation modelling analysis of a conceptual model

OBJECTIVE

Despite the well-established health benefits of physical activity, the role of exercise for eating disorders (ED) is controversial; thus dictating a need for a better understanding of the mechanisms of exercise and ED. The purpose of our study was to examine a conceptual model that hypothesizes regular exercise without psychological compulsion might impart beneficial effects for preventing and treating ED.

METHOD

University students (N = 539) completed self-report assessments of quality of life, exercise level, ED risk and exercise dependence symptoms. Structural equation modelling analysis was undertaken to examine the conceptual model's proposed relationships.

RESULTS

Mediation analysis and model comparison tests showed that the partially mediated model without the physical well-being latent construct fit the data best.

DISCUSSION

Our results provided initial support for the conceptual model by showing that the psychological benefits, but not the physical benefits, conveyed by exercise were associated with reduced ED risk.

Moderating effects of moderate-intensity physical activity in the relationship between depressive symptoms and interleukin-6 in primary care patients

OBJECTIVE

To determine whether the relationship between interleukin (IL)-6 and depressive symptoms is moderated by participation in moderate-intensity physical activity in a sample of primary care patients. Elevated inflammation has been associated with a number of poor health outcomes. Depressive symptoms may be related to higher levels of the inflammatory marker IL-6; however, previous findings are inconsistent, possibly due to unidentified moderating factors.

METHODS

A total of 107 participants, aged ≥ 40 years, were recruited in Rochester, New York, in 2006 to 2007. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression Scale-Revised, participation in moderate-intensity physical activity was measured using a modified version of the Community Health Activities Model Program for Seniors Activity Questionnaire for Older Adults, and serum IL-6 concentrations were determined using standard enzyme-linked immunosorbent assay protocols and high-sensitivity, anti-cytokine antibody pairs. A hierarchical multiple regression analysis was conducted.

RESULTS

The correlation between IL-6 and depressive symptoms was nonsignificant (r = .086, p = .40). The association between IL-6 and depressive symptoms was moderated by participation in moderate-intensity physical activity (p = .02). Among those who did not engage in moderate-intensity physical activity, higher levels of depressive symptoms were significantly associated with higher levels of IL-6 (r = .28, p = .05), whereas this association was not significant among those who did participate in moderate-intensity physical activity (r = -.13, p = .38).

CONCLUSION

Participation in moderate-intensity physical activity may buffer the risk of higher inflammation often associated with higher levels of depressive symptoms.

The effect of exercise on mental health

Including exercise for the prevention and treatment of mental disorders is a promising area of research for exercise scientists since data indicate that many of these disorders are not treated at all, and there is a significant delay in treatment. This review provides an appraisal of the recent use of exercise to prevent and treat specific mental disorders and provides a recommended framework for future progress of this research. More research is needed to overcome methodological issues to demonstrate the efficacy and effectiveness of exercise and to integrate mental and physical healthcare for widespread dissemination.

Emotional outlook on life predicts increases in physical activity among initially inactive men

This study examined the relationship between emotional outlook on life and change in physical activity among inactive adults in the Aerobics Center Longitudinal Study. A total of 2,132 sedentary adults completed a baseline medical examination and returned for a follow-up examination at least 6 months later. Participants self-reported physical activity level and emotional outlook on life. Emotional outlook on life was significantly and positively related to physical activity participation at the follow-up visit in men but not women. Men who were usually very happy and optimistic at baseline had significantly greater increases in physical activity compared to men who were not happy. Men with a more positive outlook on life (e.g., happier) may be more likely to increase physical activity levels. Physical activity interventions targeting men may be more successful if they first increase happiness.

Efficacy of exercise in reducing depressive symptoms across 5-HTTLPR genotypes

INTRODUCTION

Exercise is effective in the alleviation of depressive symptoms and may have physiological effects similar to those of selective serotonin reuptake inhibitors (SSRI). Recent research has identified the difference in treatment effects across genetic polymorphisms of the serotonin transporter polymorphic region (5-HTTLPR), in which the l allele has been associated with a better response to SSRI compared with the s allele. The purpose of the current research was to examine the antidepressant effects of exercise across 5-HTTLPR genotypes.

METHODS

Participants, ages 18–23 yr, were randomly assigned to a 5-wk exercise intervention or a no-treatment control group. Participants completed the Beck Depression Inventory before and after the intervention and provided a saliva sample for DNA analysis.

RESULTS

Exercise resulted in a significant reduction in depressive symptoms compared with the control group. In addition, individuals with at least one l allele demonstrated greater reductions in depressive symptoms compared with ss individuals.

CONCLUSIONS

The effects of exercise on depressive symptoms appear to be moderated by 5-HTTLPR genotype, suggesting that the mechanisms responsible for the alleviation of depressive symptoms are similar for exercise and SSRI treatment. Furthermore, these findings suggest that 5-HTTLPR genotype should be a factor in determining the proper line of treatment for depression.

The association of 5-HTTLPR genotype and depressive symptoms is moderated by physical activity

The s allele serotonin transporter polymorphic region (5-HTTLPR) is associated with a number of physiological mechanisms that may increase the risk of elevated depressive symptoms. However, reports of a relationship between serotonin transporter polymorphic region (5-HTTLPR) genotype and depressive symptoms have thus far been inconclusive. This heterogeneity of results suggests that other factors may be moderating the relationship between 5-HTTLPR and depressive symptoms. Higher levels of physical activity are associated with lower levels of depressive symptoms. Mechanisms responsible for this association include alterations of the serotonergic system and the hypothalamic-pituitary axis. The aim of the current study was to measure the moderating effect of physical activity on the relationship between 5-HTTLPR genotype and depressive symptoms. Participants, ages 18-23, provided a saliva sample for DNA analysis and completed questionnaires to assess depressive symptoms and physical activity. A hierarchical multiple regression analysis was conducted to examine the moderating effect of physical activity on the relationship between 5-HTTLPR genotype and depressive symptoms. Analysis revealed a significant interaction between 5-HTTLPR and physical activity (p = .010). At low levels of physical activity, individuals with at least one s allele had significantly higher levels of depressive symptoms compared to ll individuals (p = .011). This finding provides preliminary support for a moderating effect of physical activity on the relationship between 5-HTTLPR and depressive symptoms.

The antidepressant effects of running and escitalopram are associated with levels of hippocampal NPY and Y1 receptor but not cell proliferation in a rat model of depression

One hypothesis of depression is that it is caused by reduced neuronal plasticity including hippocampal neurogenesis. In this study, we compared the effects of three long-term antidepressant treatments: escitalopram, voluntary running, and their combination on hippocampal cell proliferation, NPY and the NPY-Y1 receptor mRNAs, targets assumed to be important for hippocampal plasticity and mood disorders. An animal model of depression, the Flinders Sensitive Line (FSL) rat, was used and female rats were chosen because the majority of the depressed population is females. We investigated if these treatments were correlated to immobility, swimming, and climbing behaviors, which are associated with an overall, serotonergic-like and noradrenergic-like antidepressant response, in the Porsolt swim test (PST). Interestingly, while escitalopram, running and their combination increased the number of hippocampal BrdU immunoreactive cells, the antidepressant-like effect was only detected in the running group and the group with access both to running wheel and escitalopram. Hippocampal NPY mRNA and the NPY-Y1 receptor mRNA were elevated by running and the combined treatment. Moreover, correlations were detected between NPY mRNA levels and climbing and cell proliferation and NPY-Y1 receptor mRNA levels and swimming. Our results suggest that increased cell proliferation is not necessarily associated with an antidepressant effect. However, treatments that were associated with an antidepressant-like effect did regulate hippocampal levels of mRNAs encoding NPY and/or the NPY-Y1 receptor and support the notion that NPY can stimulate cell proliferation and induce an antidepressant-like response.

A systematic review of evidence for the added benefits to health of exposure to natural environments

BACKGROUND

There is increasing interest in the potential role of the natural environment in human health and well-being. However, the evidence-base for specific and direct health or well-being benefits of activity within natural compared to more synthetic environments has not been systematically assessed.

METHODS

We conducted a systematic review to collate and synthesise the findings of studies that compare measurements of health or well-being in natural and synthetic environments. Effect sizes of the differences between environments were calculated and meta-analysis used to synthesise data from studies measuring similar outcomes.

RESULTS

Twenty-five studies met the review inclusion criteria. Most of these studies were crossover or controlled trials that investigated the effects of short-term exposure to each environment during a walk or run. This included 'natural' environments, such as public parks and green university campuses, and synthetic environments, such as indoor and outdoor built environments. The most common outcome measures were scores of different self-reported emotions. Based on these data, a meta-analysis provided some evidence of a positive benefit of a walk or run in a natural environment in comparison to a synthetic environment. There was also some support for greater attention after exposure to a natural environment but not after adjusting effect sizes for pretest differences. Meta-analysis of data on blood pressure and cortisol concentrations found less evidence of a consistent difference between environments across studies.

CONCLUSIONS

Overall, the studies are suggestive that natural environments may have direct and positive impacts on well-being, but support the need for investment in further research on this question to understand the general significance for public health.

Evaluating the effectiveness of psychosocial resilience training for heart health, and the added value of promoting physical activity: a cluster randomized trial of the READY program

BACKGROUND

Depression and poor social support are significant risk factors for coronary heart disease (CHD), and stress and anxiety can trigger coronary events. People experiencing such psychosocial difficulties are more likely to be physically inactive, which is also an independent risk factor for CHD. Resilience training can target these risk factors, but there is little research evaluating the effectiveness of such programs. This paper describes the design and measures of a study to evaluate a resilience training program (READY) to promote psychosocial well-being for heart health, and the added value of integrating physical activity promotion.

METHODS/DESIGN

In a cluster randomized trial, 95 participants will be allocated to either a waitlist or one of two intervention conditions. Both intervention conditions will receive a 10 x 2.5 hour group resilience training program (READY) over 13 weeks. The program targets five protective factors identified from empirical evidence and analyzed as mediating variables: positive emotions, cognitive flexibility, social support, life meaning, and active coping. Resilience enhancement strategies reflect the six core Acceptance and Commitment Therapy processes (values, mindfulness, defusion, acceptance, self-as-context, committed action) and Cognitive Behavior Therapy strategies such as relaxation training and social support building skills. Sessions include psychoeducation, discussions, experiential exercises, and home assignments. One intervention condition will include an additional session and ongoing content promoting physical activity. Measurement will occur at baseline, two weeks post intervention, and at eight weeks follow-up, and will include questionnaires, pedometer step logs, and physical and hematological measures. Primary outcome measures will include self-reported indicators of psychosocial well-being and depression. Secondary outcome measures will include self-reported indicators of stress, anxiety and physical activity, and objective indicators of CHD risk (blood glucose, cholesterol [mmol.L-1], triglycerides, blood pressure). Process measures of attendance, engagement and fidelity will also be conducted. Linear analyses will be used to examine group differences in the outcome measures, and the product of coefficients method will be used to examine mediated effects.

DISCUSSION

If successful, this program will provide an innovative means by which to promote psychosocial well-being for heart health in the general population. The program could also be adapted to promote well-being in other at risk population subgroups.

TRIAL REGISTRATION

ACTRN12608000017325.