Biological mechanisms underlying the role of physical fitness in health and resilience

Children's Physical Activity and Depression: A Meta-analysis

CONTEXT

Research regarding the protective effects of early physical activity on depression has yielded conflicting results.

OBJECTIVE

Our objective was to synthesize observational studies examining the association of physical activity in childhood and adolescence with depression.

DATA SOURCES

Studies (from 2005 to 2015) were identified by using a comprehensive search strategy.

STUDY SELECTION

The included studies measured physical activity in childhood or adolescence and examined its association with depression.

DATA EXTRACTION

Data were extracted by 2 independent coders. Estimates were examined by using random-effects meta-analysis.

RESULTS

Fifty independent samples (89 894 participants) were included, and the mean effect size was significant (r = -0.14; 95% confidence interval [CI] = -0.19 to -0.10). Moderator analyses revealed stronger effect sizes in studies with cross-sectional versus longitudinal designs (k = 36, r = -0.17; 95% CI = -0.23 to -0.10 vs k = 14, r = -0.07; 95% CI = -0.10 to -0.04); using depression self-report versus interview (k = 46, r = -0.15; 95% CI = -0.20 to -0.10 vs k = 4, r = -0.05; 95% CI = -0.09 to -0.01); using validated versus nonvalidated physical activity measures (k = 29, r = -0.18; 95% CI = -0.26 to -0.09 vs k = 21, r = -0.08; 95% CI = -0.11 to -0.05); and using measures of frequency and intensity of physical activity versus intensity alone (k = 27, r = -0.17; 95% CI = -0.25 to -0.09 vs k = 7, r = -0.05; 95% CI = -0.09 to -0.01).

LIMITATIONS

Limitations included a lack of standardized measures of physical activity; use of self-report of depression in majority of studies; and a small number of longitudinal studies.

CONCLUSIONS

Physical activity is associated with decreased concurrent depressive symptoms; the association with future depressive symptoms is weak.

Contribution of neuroinflammation and immunity to brain aging and the mitigating effects of physical and cognitive interventions

It is widely accepted that the brain and the immune system continuously interact during normal as well as pathological functioning. Human aging is commonly accompanied by low-grade inflammation in both the immune and central nervous systems, thought to contribute to many age-related diseases. This review of the current literature focuses first on the normal neuroimmune interactions occurring in the brain, which promote learning, memory and neuroplasticity. Further, we discuss the protective and dynamic role of barriers to neuroimmune interactions, which have become clearer with the recent discovery of the meningeal lymphatic system. Next, we consider age-related changes of the immune system and possible deleterious influences of immunosenescence and low-grade inflammation (inflammaging) on neurodegenerative processes in the normally aging brain. We survey the major immunomodulators and neuroregulators in the aging brain and their highly tuned dynamic and reciprocal interactions. Finally, we consider our current understanding of how physical activity, as well as a combination of physical and cognitive interventions, may mediate anti-inflammatory effects and thus positively impact brain aging.

Increases in Physical Activity Result in Diminishing Increments in Daily Energy Expenditure in Mice

Exercise is a common component of weight loss strategies, yet exercise programs are associated with surprisingly small changes in body weight [1-4]. This may be due in part to compensatory adaptations, in which calories expended during exercise are counteracted by decreases in other aspects of energy expenditure [1, 5-10]. Here we examined the relationship between a rodent model of voluntary exercise- wheel running- and total daily energy expenditure. Use of a running wheel for 3 to 7 days increased daily energy expenditure, resulting in a caloric deficit of ∼1 kcal/day; however, total daily energy expenditure remained stable after the first week of wheel access, despite further increases in wheel use. We hypothesized that compensatory mechanisms accounted for the lack of increase in daily energy expenditure after the first week. Supporting this idea, we observed a decrease in off-wheel ambulation when mice were using the wheels, indicating behavioral compensation. Finally, we asked whether individual variation in wheel use within a group of mice would be associated with different levels of daily energy expenditure. Despite a large variation in wheel running, we did not observe a significant relationship between the amount of daily wheel running and total daily energy expenditure or energy intake across mice. Together, our experiments support a model in which the transition from sedentary to light activity is associated with an increase in daily energy expenditure, but further increases in physical activity produce diminishingly small increments in daily energy expenditure.

A review of the physiological and psychological health and wellbeing of naval service personnel and the modalities used for monitoring

Naval cohorts rely heavily on personnel to ensure the efficient running of naval organisations. As such, the wellbeing of personnel is essential. In an occupational setting, naval service personnel experience a variety of physiological and psychological stressors. Most naval services arrange annual physical fitness and body composition tests to ensure the physical readiness of personnel. However, these tests only evaluate a small amount of physiological capabilities. Components such as aerobic and strength capabilities are assessed, however, other components of physical fitness such as speed, agility, anaerobic capacity and flexibility are not. In addition to the physical capabilities, personnel are impacted by fatigue, nutrition and psychological stressors such as copping in stressful situations or dealing with time away from family and friends. This review will discuss the physiological and psychological factors that affect personnel's wellbeing. In addition to this, it will also evaluate the methods that are used to assess both physiological and psychological wellbeing.

Active Lifestyle Is Associated With Reduced Dyspnea and Greater Life Satisfaction in Spinal Cord Injury

OBJECTIVE

To assess the relations between measures of activity with dyspnea and satisfaction with life in chronic spinal cord injury (SCI).

DESIGN

Cross-sectional survey.

SETTING

Five SCI centers.

PARTICIPANTS

Between July 2012 and March 2015, subjects (N=347) with traumatic SCI ≥1 year after injury who used a manual wheelchair or walked with or without an assistive device reported hours spent away from home or yard on the previous 3 days, sports participation, and planned exercise.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Satisfaction with Life Scale (SWLS) and dyspnea. Dyspnea was defined as shortness of breath when hurrying on the level or going up a slight hill, going slower than people the same age on the level because of breathlessness, or stopping for breath when going at your own pace, or after about 100yd (or after a few minutes) on the level.

RESULTS

Dyspnea prevalence was 30%. Adjusting for asthma or chronic obstructive pulmonary disease, mobility mode, race, and season, there was a significant linear trend between greater SWLS scores and quartiles of time spent away from the home or yard (P=.0002). SWLS score was greater if participating in organized sports (P=.01), although was not significantly greater with planned exercise (P=.093). Planned exercise was associated with a reduced odds ratio (OR) of dyspnea (.57; 95% confidence interval [CI], .34-.95; P=.032), but organized sports was not (P=.265). Dyspnea was not significantly increased in persons who spent the fewest hours outside their home or yard (≤7h) compared with people who spent the most hours outside their home or yard (>23h) (OR=1.69; 95% CI, 0.83-3.44; P=.145).

CONCLUSIONS

In SCI, a planned exercise program is associated with less dyspnea. An active lifestyle characterized by greater time spent away from home or yard and sports participation is associated with greater SWLS scores.

Physical activity buffers fatigue only under low chronic stress

Fatigue is one of the most commonly reported complaints in the general population. As physical activity (PA) has been shown to have beneficial effects, we hypothesized that everyday life PA improves fatigue. Thirty-three healthy students (21 women, 22.8 ± 3.3 years, 21.7 ± 2.3 kg/m(2)) completed two ambulatory assessment periods. During five days at the beginning of the semester (control condition) and five days during final examination preparation (examination condition), participants repeatedly reported on general fatigue (awakening, 10 am, 2 pm, 6 pm and 9 pm) by means of an electronic diary, collected saliva samples for the assessment of cortisol and α-amylase immediately after providing information on fatigue and wore a triaxial accelerometer to continuously record PA. Self-perceived chronic stress was assessed as a moderator. Using hierarchical linear modeling, including PA, condition (control vs. examination), sex and chronic stress as predictors, PA level during the 15 min prior to data entry did not predict momentary fatigue level. Furthermore, there was no effect of condition. However, a significant cross-level interaction of perceived chronic stress with PA was observed. In fact, the (negative) relationship between PA and fatigue was stronger in those participants with less chronic stress. Neither cortisol nor α-amylase was significantly related to physical activity or fatigue. Our study showed an immediate short-term buffering effect of everyday life PA on general fatigue, but only when experiencing lower chronic stress. There seems to be no short-term benefit of PA in the face of higher chronic stress. These findings highlight the importance of considering chronic stress when evaluating the effectiveness of PA interventions in different target populations, in particular among chronically stressed and fatigued subjects.

Association between regular physical exercise and depressive symptoms mediated through social support and resilience in Japanese company workers: a cross-sectional study

BACKGROUND

Regular physical exercise has been reported to reduce depressive symptoms. Several lines of evidence suggest that physical exercise may prevent depression by promoting social support or resilience, which is the ability to adapt to challenging life conditions. The aim of this study was to compare depressive symptoms, social support, and resilience between Japanese company workers who engaged in regular physical exercise and workers who did not exercise regularly. We also investigated whether regular physical exercise has an indirect association with depressive symptoms through social support and resilience.

METHODS

Participants were 715 Japanese employees at six worksites. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression (CES-D) scale, social support with the short version of the Social Support Questionnaire (SSQ), and resilience with the 14-item Resilience Scale (RS-14). A self-report questionnaire, which was extracted from the Japanese version of the Health-Promoting Lifestyle Profile, was used to assess whether participants engage in regular physical exercise, defined as more than 20 min, three or more times per week. The group differences in CES-D, SSQ, and RS-14 scores were investigated by using analysis of covariance (ANCOVA). Mediation analysis was conducted by using Preacher and Hayes' bootstrap script to assess whether regular physical exercise is associated with depressive symptoms indirectly through resilience and social support.

RESULTS

The SSQ Number score (F = 4.82, p = 0.03), SSQ Satisfaction score (F = 6.68, p = 0.01), and RS-14 score (F = 6.01, p = 0.01) were significantly higher in the group with regular physical exercise (n = 83) than in the group without regular physical exercise (n = 632) after adjusting for age, education, marital status, and job status. The difference in CES-D score was not significant (F = 2.90, p = 0.09). Bootstrapping revealed significant negative indirect associations between physical exercise and CES-D score through the SSQ Number score (bias-corrected and accelerated confidence interval (BCACI) = -0.61 to -0.035; 95 % confidence interval (CI)), SSQ Satisfaction score (BCACI = -0.92 to -0.18; 95 % CI), and RS-14 score (BCACI = -1.89 to -0.094; 95 % CI).

CONCLUSION

Although we did not find a significant direct association between exercise and depressive symptoms, exercise may be indirectly associated with depressive symptoms through social support and resilience. Further investigation is warranted.

Characterization of Vulnerable and Resilient Spanish Adolescents in Their Developmental Contexts

Research on resilience and vulnerability can offer very valuable information for optimizing design and assessment of interventions and policies aimed at fostering adolescent health. This paper used the adversity level associated with family functioning and the positive adaptation level, as measured by means of a global health score, to distinguish four groups within a representative sample of Spanish adolescents aged 13-16 years: maladaptive, resilient, competent and vulnerable. The aforementioned groups were compared in a number of demographic, school context, peer context, lifestyles, psychological and socioeconomic variables, which can facilitate or inhibit positive adaptation in each context. In addition, the degree to which each factor tended to associate with resilience and vulnerability was examined. The majority of the factors operated by increasing the likelihood of good adaptation in resilient adolescents and diminishing it in vulnerable ones. Overall, more similarities than differences were found in the factors contributing to explaining resilience or vulnerability. However, results also revealed some differential aspects: psychological variables showed a larger explicative capacity in vulnerable adolescents, whereas factors related to school and peer contexts, especially the second, showed a stronger association with resilience. In addition, perceived family wealth, satisfaction with friendships and breakfast frequency only made a significant contribution to the explanation of resilience. The current study provides a highly useful characterization of resilience and vulnerability phenomena in adolescence.

Work, household, and leisure-time physical activity and risk of mortality in the EPIC-Spain cohort

OBJECTIVE

Large-scale longitudinal data on the association of domain-specific physical activity (PA) and mortality is limited. Our objective was to evaluate the association of work, household (HPA), and leisure time PA (LTPA) with overall and cause-specific mortality in the EPIC-Spain study.

METHODS

38,379 participants (62.4% women), 30-65years old, and free of chronic disease at baseline were followed-up from recruitment (1992 - 1996) to December 31st, 2008 to ascertain vital status and cause of death. PA was evaluated at baseline and at a 3-year follow-up with a validated questionnaire (EPIC-PAQ) and combined variables were used to classify the participants by sub-domains of PA. Associations with overall, cancer, and cardiovascular mortality risks were assessed using competing risk Cox regression models adjusted by potential confounders.

RESULTS

After 13.6years of mean follow-up, 1371 deaths were available for analyses. HPA was strongly associated to reduced overall (hazard ratio (HR) for Q4 vs. Q1=0.47 (0.34, 0.64)) and cause-specific mortalities in women and to lower cancer mortality in men (P for trend=0.004), irrespective of age, education, and lifestyle and morbidity variables. LTPA was associated with lower mortality in women (HR for Q4 vs. Q1=0.71 (0.52, 0.98)), but not men. No relationships were found between sedentariness at work and overall mortality.

CONCLUSIONS

HPA was associated to lower mortality risk in men and women from the EPIC-Spain cohort, whereas LTPA also contributed to reduce risk of death in women. Considering the large proportion of total daily PA that HPA represents in some population groups, these results are of public health importance.

Is There an Association of Physical Activity with Brain Volume, Behavior, and Day-to-day Functioning? A Cross Sectional Design in Prodromal and Early Huntington Disease

BACKGROUND

Huntington disease (HD) is a genetic neurodegenerative disease leading to progressive motor, cognitive, and behavioral decline. Subtle changes in these domains are detectable up to 15 years before a definitive motor diagnosis is made. This period, called prodromal HD, provides an opportunity to examine lifestyle behaviors that may impact disease progression.

THEORETICAL FRAMEWORK

Physical activity relates to decreased rates of brain atrophy and improved cognitive and day-to-day functioning in Alzheimer disease and healthy aging populations. Previous research has yielded mixed results regarding the impact of physical activity on disease progression in HD and paid little attention to the prodromal phase.

METHODS

We conducted analyses of associations among current physical activity level, current and retrospective rate of change for hippocampus and striatum volume, and cognitive, motor, and day-to-day functioning variables. Participants were 48 gene-expanded cases with prodromal and early-diagnosed HD and 27 nongene-expanded control participants. Participants wore Fitbit Ultra activity monitors for three days and completed the self-reported International Physical Activity Questionnaire (IPAQ). Hippocampal and striatal white matter volumes were measured using magnetic resonance imaging. Cognitive tests included the Stroop Color and Word Test, and the Symbol Digit Modalities Test (SDMT). Motor function was assessed using the Unified Huntington's Disease Rating Scale total motor score (TMS). Day-to-day functioning was measured using the World Health Organization Disability Assessment Schedule (WHODAS) version 2.0.

RESULTS

Higher Fitbit activity scores were significantly related to better scores on the SDMT and WHODAS in case participants but not in controls. Fitbit activity scores tracked better with TMS scores in the group as a whole, though the association did not reach statistical significance in the case participants. Higher Fitbit activity scores related to less day-to-day functioning decline in retrospective slope analyses. Fitbit activity scores did not differ significantly between cases and controls.

CONCLUSIONS

This is the first known study examining the associations between activity level and imaging, motor, cognitive, and day-to-day functioning outcomes in prodromal and early HD. Preliminary results suggest physical activity positively correlates with improved cognitive and day-to-day functioning and possibly motor function in individuals in the prodromal and early phase of the condition.

Can Exercise Make You Smarter, Happier, and Have More Neurons? A Hormetic Perspective

Exercise can make you smarter, happier and have more neurons depending on the dose (intensity) of the training program. It is well recognized that exercise protocols induce both positive and negative effects depending on the intensity of the exercise, among other key factors, a process described as a hormetic-like biphasic dose-response. However, no evidences have been reported till very recently about the biphasic response of some of the potential mediators of the exercise-induced actions. This hypothesis and theory will focus on the adult hippocampal neurogenesis (AHN) as a putative physical substrate for hormesis responses to exercise in the context of exercise-induced actions on cognition and mood, and on the molecular pathways which might potentially be mediating these actions.

'Blood doping' from Armstrong to prehabilitation: manipulation of blood to improve performance in athletes and physiological reserve in patients

Haemoglobin is the blood’s oxygen carrying pigment and is encapsulated in red blood corpuscles. The concentration of haemoglobin in blood is dependent on both its total mass in the circulation (tHb-mass) and the total plasma volume in which it is suspended. Aerobic capacity is defined as the maximum amount of oxygen that can be consumed by the body per unit time and is one measure of physical fitness. Observations in athletes who have undergone blood doping or manipulation have revealed a closer relationship between physical fitness (aerobic capacity) and total haemoglobin mass (tHb-mass) than with haemoglobin concentration ([Hb]). Anaemia is defined by the World Health Organisation (WHO) as a haemoglobin concentration of <130 g/L for men and <120 g/L for women. Perioperative anaemia is a common problem and is associated with increased mortality and morbidity following surgery. Aerobic capacity is also associated with outcome following major surgery, with less fit patients having a higher incidence of mortality and morbidity after surgery. Taken together, these observations suggest that targeted preoperative elevation of tHb-mass may raise aerobic capacity both directly and indirectly (by augmenting preoperative exercise initiatives- ‘prehabilitation’) and thus improve postoperative outcome. This notion in turn raises a number of questions. Which measure ([Hb] or tHb-mass) has the most value for the description of oxygen carrying capacity? Which measure has the most utility for targeting therapies to manipulate haemoglobin levels? Do the newer agents being used for blood manipulation (to increase tHb-mass) in elite sport have utility in the clinical environment? This review explores the literature relating to blood manipulation in elite sport as well as the relationship between perioperative anaemia, physical fitness and outcome following surgery, and suggests some avenues for exploring this area further.

Gut Microbiota Modification: Another Piece in the Puzzle of the Benefits of Physical Exercise in Health?

Regular physical exercise provides many health benefits, protecting against the development of chronic diseases, and improving quality of life. Some of the mechanisms by which exercise provides these effects are the promotion of an anti-inflammatory state, reinforcement of the neuromuscular function, and activation of the hypothalamic-pituitary-adrenal (HPA) axis. Recently, it has been proposed that physical exercise is able to modify gut microbiota, and thus this could be another factor by which exercise promotes well-being, since gut microbiota appears to be closely related to health and disease. The purpose of this paper is to review the recent findings on gut microbiota modification by exercise, proposing several mechanisms by which physical exercise might cause changes in gut microbiota.

Anxiety and anxious-depression in Parkinson's disease over a 4-year period: a latent transition analysis

BACKGROUND

Depression and anxiety in Parkinson's disease are common and frequently co-morbid, with significant impact on health outcome. Nevertheless, management is complex and often suboptimal. The existence of clinical subtypes would support stratified approaches in both research and treatment.

METHOD

Five hundred and thirteen patients with Parkinson's disease were assessed annually for up to 4 years. Latent transition analysis (LTA) was used to identify classes that may conform to clinically meaningful subgroups, transitions between those classes over time, and baseline clinical and demographic features that predict common trajectories.

RESULTS

In total, 64.1% of the sample remained in the study at year 4. LTA identified four classes, a 'Psychologically healthy' class (approximately 50%), and three classes associated with psychological distress: one with moderate anxiety alone (approximately 20%), and two with moderate levels of depression plus moderate or severe anxiety. Class membership tended to be stable across years, with only about 15% of individuals transitioning between the healthy class and one of the distress classes. Stable distress was predicted by higher baseline depression and psychiatric history and younger age of onset of Parkinson's disease. Those with younger age of onset were also more likely to become distressed over the course of the study.

CONCLUSIONS

Psychopathology was characterized by relatively stable anxiety or anxious-depression over the 4-year period. Anxiety, with or without depression, appears to be the prominent psychopathological phenotype in Parkinson's disease suggesting a pressing need to understanding its mechanisms and improve management.

Constrained Total Energy Expenditure and Metabolic Adaptation to Physical Activity in Adult Humans

Current obesity prevention strategies recommend increasing daily physical activity, assuming that increased activity will lead to corresponding increases in total energy expenditure and prevent or reverse energy imbalance and weight gain [1-3]. Such Additive total energy expenditure models are supported by exercise intervention and accelerometry studies reporting positive correlations between physical activity and total energy expenditure [4] but are challenged by ecological studies in humans and other species showing that more active populations do not have higher total energy expenditure [5-8]. Here we tested a Constrained total energy expenditure model, in which total energy expenditure increases with physical activity at low activity levels but plateaus at higher activity levels as the body adapts to maintain total energy expenditure within a narrow range. We compared total energy expenditure, measured using doubly labeled water, against physical activity, measured using accelerometry, for a large (n = 332) sample of adults living in five populations [9]. After adjusting for body size and composition, total energy expenditure was positively correlated with physical activity, but the relationship was markedly stronger over the lower range of physical activity. For subjects in the upper range of physical activity, total energy expenditure plateaued, supporting a Constrained total energy expenditure model. Body fat percentage and activity intensity appear to modulate the metabolic response to physical activity. Models of energy balance employed in public health [1-3] should be revised to better reflect the constrained nature of total energy expenditure and the complex effects of physical activity on metabolic physiology.

Charting the landscape of priority problems in psychiatry, part 2: pathogenesis and aetiology

This is the second of two companion papers proposing priority problems for research on mental disorders. Whereas the first paper focuses on questions of nosology and diagnosis, this Personal View concerns pathogenesis and aetiology of psychiatric diseases. We hope that this (non-exhaustive and subjective) list of problems, nominated by scientists and clinicians from different fields and institutions, provides guidance and perspectives for choosing future directions in psychiatric science.

The health-enhancing efficacy of Zumba® fitness: An 8-week randomised controlled study

The purpose of this study was to gain a holistic understanding of the efficacy of Zumba® fitness in a community-recruited cohort of overweight and physically inactive women by evaluating (i) its physiological effects on cardiovascular risk factors and inflammatory biomarkers and (ii) its mental health-enhancing effects on factors of health-related quality of life (HRQoL). Participants were randomly assigned to either engagement in one to two 1 h classes of Zumba® fitness weekly (intervention group; n = 10) or maintenance of habitual activity (control group; n = 10). Laboratory assessments were conducted pre- (week 0) and post-intervention (week 8) with anthropometric, physiological, inflammatory and HRQoL data collected. In the intervention group, maximal oxygen uptake significantly increased (P < 0.05; partial η(2) = 0.56) by 3.1 mL · kg(-1) · min(-1), per cent body fat significantly decreased (P < 0.05; partial η(2) = 0.42) by -1.2%, and interleukin-6 and white blood cell (WBC) count both significantly decreased (P < 0.01) by -0.4 pg · mL(-1) (partial η(2) = 0.96) and -2.1 × 10(9) cells · L(-1) (partial η(2) = 0.87), respectively. Large magnitude enhancements were observed in the HRQoL factors of physical functioning, general health, energy/fatigue and emotional well-being. When interpreted in a community-based physical activity and psychosocial health promotion context, our data suggest that Zumba® fitness is indeed an efficacious health-enhancing activity for adults.

Greater Leisure Time Physical Activity Is Associated with Lower Allostatic Load in White, Black, and Mexican American Midlife Women: Findings from the National Health and Nutrition Examination Survey, 1999 through 2004

BACKGROUND

Allostatic load is a useful construct to understand how social and environmental conditions get under the skin to affect health. To date, few studies have examined health-enhancing lifestyle behaviors and their potential benefits in reducing allostatic load. The purpose of this study was to investigate the contributions of leisure time physical activity on level of allostatic load among White, Black, and Mexican American midlife women.

METHODS

Data were from the National Health and Nutrition Examination Survey, 1999 through 2004 (n = 1,680, women ages 40-59). All analyses were weighted. Negative binomial regression was used to model a summative count measure of allostatic load (M = 2.30). Models were also computed to estimate adjusted predicted allostatic load for given levels of physical activity, and by race/ethnicity for each age category (40-44, 45-49, 50-54, 55-59), controlling for other demographics and medication use.

FINDINGS

Higher levels of physical activity were associated significantly with lower levels of allostatic load, independent of demographics. Compared with White women ages 40 to 44, all other racial/ethnic-by-age groups had significantly higher allostatic load. Higher socioeconomic status was associated with a lower allostatic load. Adjusted prediction models demonstrated associations between greater levels of physical activity and lower allostatic load for all ages and racial/ethnic groups.

CONCLUSIONS

Our findings suggest physical activity may ameliorate some of the effects of cumulative physiological dysregulation and subsequent disease burden in midlife women. Programs and policies that encourage and promote healthy aging and provide opportunities for a diversity of women to engage in health-enhancing lifestyle practices such as physical activity are recommended.

Optimizing the Exercise Prescription for Depression: The Search for Biomarkers of Response

There is growing support for the efficacy of exercise interventions for the treatment of individuals who present with mild-to-moderate depression. The variability in treatment response across studies and individuals suggests that the efficacy of exercise for depression will be most optimal when prescribed to individuals who are most prone to respond. The present article reviews contemporary theoretical accounts and recent empirical data pointing to neuroinflammatory states and neurotrophin production as possible biomarkers of the antidepressant response to exercise. The larger exercise and depression literatures provide justification for elevated levels of pro-inflammatory cytokines and deficits in BDNF production as putative matching variables. Although there is some empirical support for these hypotheses, it is clear that this research warrants replication and extension. We offer a few suggestions for future research in this emerging area.

Risk factors for the development of psychopathology following trauma

Traumatic experiences can lead to a range of mental health problems with posttraumatic stress disorder (PTSD) leading as the most documented disorder following trauma. Epidemiological research has found the rate of exposure to trauma to far outweigh the prevalence of PTSD. Indicating that most people do not develop PTSD following a traumatic event, this phenomenon has led to an interest in evaluating risk factors to determine who develops PTSD. Risk factors for the development of psychopathology following trauma exposure fall into three categories: pre-trauma, peri-trauma and post-trauma factors. Pre-trauma factors can include age, gender, race/ethnicity, education, prior psychopathology, and neurobiological factors. Peri-trauma factors can include the duration/severity of trauma experience and the perception that the trauma has ended. Post-trauma factors can include access to needed resources, social support, specific cognitive patterns, and physical activity. To date, several important risk factors have been found to impact the risk of developing PTSD including gender, age, education, IQ, race and ethnicity, sexual orientation, pre-trauma psychopathology, prior trauma exposure, familial psychiatric history, and neurobiological factors. This article outlines the state of research findings on pretraumatic, peritraumatic, and posttraumatic risk factors for the development of PTSD and associated psychopathology following trauma.

Improvement in Depressive Symptoms Is Associated with Reduced Oxidative Damage and Inflammatory Response in Type 2 Diabetic Patients with Subsyndromal Depression: The Results of a Randomized Controlled Trial Comparing Psychoeducation, Physical Exercise, and Enhanced Treatment as Usual

Aims. To examine one-year changes in oxidative damage and inflammation level in type 2 diabetic patients undergoing behavioral treatment for subsyndromal depression. Materials and Methods. A randomized controlled comparison of psychoeducation (A), physical exercise (B), and enhanced treatment as usual (C) was performed in 209 eligible subjects in a tertiary diabetes care setting. Depressive symptoms (primary outcome) and selected biomarkers of oxidative damage and inflammation (secondary outcomes) were assessed at baseline and six- and twelve-month follow-up. Results. Out of the 74, 67, and 68 patients randomised into groups A, B, and C, respectively, 201 completed the interventions, and 179 were analysed. Participants in all three groups equally improved in depressive symptoms from baseline to one-year follow-up (repeated measures ANOVA; F = 12.51, p < 0.0001, η (2) = 0.07). Urinary 8-oxo-deoxyguanosine (u-8-oxodG) decreased (F = 10.66, p < 0.0001, η (2) = 0.06), as did sialic acid and leukocytes (F = 84.57, η (2) = 0.32 and F = 12.61, η (2) = 0.07, resp.; p < 0.0001), while uric acid increased (F = 12.53, p < 0.0001, η (2) = 0.07) in all subjects during one year. Improvement of depressive symptoms at 6 months significantly predicted one-year reduction in u-8-oxodG (β = 0.15, p = 0.044). Conclusion. Simple behavioral interventions are capable not only of alleviating depressive symptoms, but also of reducing the intensity of damaging oxidative/inflammatory processes in type 2 diabetic patients with subsyndromal depression. This trial is registered with ISRCTN05673017.