Physical exercise counteracts genetic susceptibility to depression

The relationship between BDNF and physical activity on depression

BACKGROUND/OBJECTIVE

Major depressive disorder (MDD) is one of the leading causes of disease burden and disability worldwide. Brain-derived neurotrophic factor (BDNF) seems to have an important role in the molecular mechanisms underlying MDD aetiology, given its implication in regulating neuronal plasticity. There is evidence that physical activity (PA) improves depressive symptoms, with a key role of BDNF in this effect. We aim to perform a systematic review examining the relationship between the BDNF Val66Met polymorphism and the BDNF protein, PA and MDD.

METHODS

Both observational and experimental design original articles or systematic reviews were selected, according to the PRISMA statement.

RESULTS

Six studies evaluated the Val66Met polymorphism, suggesting a greater impact of physical activity on depression depending on the Val66Met genotype. More discordant findings were observed among the 13 studies assessing BDNF levels with acute or chronic exercise interventions, mainly due to the high heterogeneity found among intervention designs, limited sample size, and potential bias.

CONCLUSIONS

Overall, there is cumulative evidence supporting the potential role of BDNF in the interaction between PA and MDD. However, this review highlights the need for further research with more homogeneous and standardised criteria, and pinpoints important confounding factors that must be considered in future studies to provide robust conclusions.

Association between Psychopathological Symptoms and Aggression and Selected Biochemical Parameters in Adolescents with Behavioural and Emotional Disturbances

Behavioural and emotional disturbances (F92.8) are the most recognized disorders in a developmental psychiatry. As the problem is still alarmingly increasing, the searches for their etiopathogenesis and more effective preventing and therapy methods are required. The aim of the study was to assess the association between the quality of life, some psychopathological features, concentrations of selected immunoprotective (brain-derived neurotrophin, BDNF), and endocrine (cortisol, F) factors while adolescent disturbances. The study was performed in 123 inpatients of a psychiatric ward with F92.8 diagnosis, aged 13-18 years. The complete patients' interview, physical examination, and routine laboratory tests, including serum F and BDNF tests, were performed. All patients completed standardized questionnaires to estimate: the severity of psychopathological symptoms (SCL-90), the level of aggression (Buss-Perry). The changes in the plasma BDNF and F concentrations were shown in patients raised in foster homes and institutions. The significantly lower BDNF was observed in youth from foster and suicide-experienced families. The more severe psychopathological symptoms, especially aggression and hostility, were found in these ones, who abused alcohol, attempted suicide, had lower self-esteem and cognitive processes, and were lacking safety in dysfunctional families.

Dorsal Dentate Gyrus, a Key Regulator for Mood and Psychiatric Disorders

The dentate gyrus, a "gate" that controls the flow of information into the hippocampus, is critical for learning, memory, spatial navigation, and mood regulation. Several lines of evidence have demonstrated that deficits in dentate granule cells (DGCs) (e.g., loss of DGCs or genetic mutations in DGCs) contribute to the development of various psychiatric disorders, such as depression and anxiety disorders. Whereas ventral DGCs are believed to be critical for mood regulation, the functions of dorsal DGCs in this regard remain elusive. Here, we review the role of DGCs, in particular the dorsal DGCs, in the regulation of mood, their functional relationships with DGC development, and the contributions of dysfunctional DGCs to mental disorders.

Associations of Brain-Derived Neurotropic Factor rs6265 Gene Polymorphism with Personality Dimensions among Athletes

Brain-Derived Neurotropic Factor (BDNF) is one of the essential mediating factors of exercise-induced neuroplasticity, but the underlying molecular mechanisms of exercise-induced neuroplasticity are still largely unknown. Personality dimensions differentiate individuals and depend on genes and environmental factors. The dimensions of openness to experience, emotional stability, extraversion and conscientiousness have been reported to be positively related to performance; considering agreeableness, a negative relation with sports performance was emphasized. However, not enough effort has been put into investigating the relationship between genetic polymorphisms affecting psychological abilities and competitive power sports. The aim of this study was to investigate the association of the rs6265 polymorphism of BDNF with personality dimensions in martial arts athletes. The study was conducted among martial arts athletes. The study group included 258 volunteers (martial arts athletes (n = 106) and controls (n = 152). BDNF polymorphism testing was performed using the real-time PCR method; personality dimensions were assessed using standardized NEO-FFI questionnaires. All analyses were performed using STATISTICA 13. We observed that martial arts athletes’ G/G genotypes compared to the control group G/G genotypes presented significantly higher severity of personality dimension “conscientiousness”. In comparison with the controls, the case group subjects had significantly higher scores in the dimension extraversion (M 6.89 vs. M 6.43, p = 0.0405) and conscientiousness/scale (M 7.23 vs. M 5.89, p < 0.0001). The results of 2 × 3 factorial ANOVA noticed a statistically significant effect of combined factor BDNF rs6265 genotype of martial arts/control (F2,252 = 3.11, p = 0.0465, η2 = 0.024). Additionally, we observed that the results of 2 × 3 factorial ANOVA showed a statistically significant influence of combined factor BDNF rs6265 of genotype martial arts/ control (F2,252 = 6.16, p = 0.0024, η2 = 0.047). The combination of the analysis of personality dimensions with genetics—as in the case of the polymorphism of the BDNF gene related to neuroplasticity—indicates that neurobiology cannot be ignored in educating sports champions. We already know that this is related to genetics. However, little is still known about the influence of personality traits on sports performance. We observed that martial arts athletes’ G/G genotypes, in comparison to the control group’s G/G genotypes, presented significantly higher severity of personality dimension “conscientiousness”. This is worthy of further analysis and probably longitudinal studies on a more numerous group of athletes.

Interaction Effect between Physical Activity and the BDNF Val66Met Polymorphism on Depression in Women from the PISMA-ep Study

The relationship between depression and the Val66Met polymorphism at the brain-derived neurotrophic factor gene (BDNF), has been largely studied. It has also been related to physical activity, although the results remain inconclusive. The aim of this study is to investigate the relationship between this polymorphism, depression and physical activity in a thoroughly characterised sample of community-based individuals from the PISMA-ep study. A total of 3123 participants from the PISMA-ep study were genotyped for the BDNF Val66Met polymorphism, of which 209 had depression. Our results are in line with previous studies reporting a protective effect of physical activity on depression, specifically in light intensity. Interestingly, we report a gene-environment interaction effect in which Met allele carriers of the BDNF Val66Met polymorphism who reported more hours of physical activity showed a decreased prevalence of depression. This effect was observed in the total sample (OR = 0.95, 95%CI = 0.90–0.99, p = 0.027) and was strengthened in women (OR = 0.93, 95%CI = 0.87–0.98, p = 0.019). These results highlight the potential role of physical activity as a promising therapeutic strategy for preventing and adjuvant treatment of depression and suggest molecular and genetic particularities of depression between sexes.

Basal myokine levels are associated with quality of life and depressed mood in older adults

In an aging society, late-life depression has become an increasing problem. There is evidence that physical activity ameliorates depressive symptoms and increases the quality of life (QoL). However, the underlying mechanisms are still poorly understood. Myokines are molecules secreted in response to muscle contraction. Some of them can cross the blood-brain barrier, making them promising candidates for mediating the beneficial effects of physical activity on mood. The present study aims to compare circulating myokine levels to depression/QoL in older athletes and controls. 55 athletes, 57 controls >59 years were enrolled. The assessment included ergometry, magnetic resonance imaging, blood withdrawal, and neuropsychological testing. Serum interleukin-6 (IL-6), irisin, brain-derived neurotrophic factor (BDNF), kynurenine, and cathepsin B were analyzed and compared to surrogates of depression and quality of life. Athletes presented with higher levels of Cathepsin B. Among controls, all myokines but irisin were associated with age. Also, among controls, kynurenine and IL-6 correlated inversely with specific dimensions of quality of life questionnaires, and IL-6 further with depressive symptoms and decreased physical performance. No such associations could be found among athletes. Irisin levels were inversely associated with mild depression and low-grade white matter-lesions in the brain and predicted impaired QoL. The circulating levels of several myokines/muscle activity-related factors appear to be associated with depressive symptoms and impaired QoL among older adults. However, in athletes, some of these connections seem ameliorated, suggesting additional stressors (as f.e. age) or a different pathomechanism among athletes.

High intensity endurance training is associated with better quality of life, but not with improved cognitive functions in elderly marathon runners

Impairment of cognitive functions in advanced age leads to a reduced quality of life and impaired ability to perform everyday tasks. The positive impact of physical exercise on the quality of life and well-being, also at a later age, is well established. However, the effect of endurance exercises, including long distance running and cycling, on cognitive function and mental health within the elderly population has still to be elucidated. To this end, elderly active marathoners (N = 50) aged over 60 years and non-athlete controls (N = 49) were followed for four years. Cognitive function was assessed using the CERAD test battery. In addition, the Short Form Health Survey (SF-36) was applied to assess self-reported physical, mental, and emotional health. Except for age, sex and education-corrected z-values of the test “Word list recall”, with marathon runners showing a decline compared to an improvement in controls (p < 0.05), there was no statistically significant difference in time trend between groups. In contrast, concerning self-reported health, scores in all eight domains of the SF-36 remained stable over time and, in nearly all of them, marathon runners showed higher self-reported health than controls. The results indicated that extensive endurance exercise is associated with improved subjective health but does not lead to better scores in cognitive performance tests in elderly persons.

Do health-related factors predict major depression? A longitudinal epidemiologic study

Major depressive disorder (MDD) is a leading cause of global disease burden. Hence, examining the role of risk and protective factors for MDD is an important target in psychological research. Various studies showed that obesity, smoking, and alcohol consumption are related to depressive symptoms. In contrast, physical activity has been found to be a protective factor. The present population-based study tested whether these health-related factors are prospectively associated with incidence of MDD. Data were taken from the Dresden Predictor Study, which was designed to investigate risk and protective factors of mental health in young women. It included two assessments approximately 17 months apart. Results of single logistic regression analyses showed that being overweight, being a smoker, and being in a high-risk drinking group at baseline were predictive of developing MDD at follow-up. Engaging in regular physical activity and having good physical health were found to be protective factors of MDD. However, being in a medium-risk drinking group was not predictive of incidence of MDD, and irregular physical activity was not a protective factor. This is the first prospective, longitudinal study to show that obesity, smoking, and high-risk drinking are predictive of new onsets of MDD and that physical health is a protective factor. These data provide promising avenues for future research.

A self-determination approach to the understanding of the impact of physical activity on depressive symptoms

The purpose was to test a new motivational sequence. It was hypothesized that more autonomous forms of motivation would predict the intensity of physical activity (PA), which in turn, would predict depressive symptoms. In order to evaluate self-determined motivation, the Self-Determination Index (SDI) was used. Because the reasons that can lead a person to engage in walking, moderate PA, or vigorous PA may be different, 3 independent self-determination indexes were measured (SDIWalking, SDIModerate, and SDIVigorous). It was also measured the metabolic equivalent of task values (METs) for walking, moderate, and vigorous PA, as well as the depressive symptoms. The sample consisted of 357 college students whose ages ranged from 18 to 29 years. Structural equation modeling was used to test the hypothesized model. The indices of fit showed that the revised model fits the data reasonably well: S-Bχ²₍₁₁₎  = 14.83, p = .190; χ² /df = 1.35; *comparative fit index = .99; *root mean square error of approximation = .03, 90% CI [.000, .068]; standardised root mean square residual = .03. It was found that vigorous PA is the only intensity that predicts depressive symptoms. In other words, SDIV-predicted vigorous PA (measured as MET_S V), which subsequently predicted less depressive symptoms (SDIV → MET_S V → Depressive symptoms). Further research should investigate the effects of vigorous PA on depressive symptoms.

Adult hippocampal neurogenesis: an important target associated with antidepressant effects of exercise

Depression is a prevalent devastating mental disorder that affects the normal life of patients and brings a heavy burden to whole society. Although many efforts have been made to attenuate depressive/anxiety symptoms, the current clinic antidepressants have limited effects. Scientists have long been making attempts to find some new strategies that can be applied as the alternative antidepressant therapy. Exercise, a widely recognized healthy lifestyle, has been suggested as a therapy that can relieve psychiatric stress. However, how exercise improves the brain functions and reaches the antidepressant target needs systematic summarization due to the complexity and heterogeneous feature of depression. Brain plasticity, especially adult neurogenesis in the hippocampus, is an important neurophysiology to facilitate animals for neurogenesis can occur in not only humans. Many studies indicated that an appropriate level of exercise can promote neurogenesis in the adult brains. In this article, we provide information about the antidepressant effects of exercise and its implications in adult neurogenesis. From the neurogenesis perspective, we summarize evidence about the effects of exercise in enhancing neurogenesis in the hippocampus through regulating growth factors, neurotrophins, neurotransmitters and metabolism as well as inflammations. Taken together, a large number of published works indicate the multiple benefits of exercise in the brain functions of animals, particularly brain plasticity like neurogenesis and synaptogenesis. Therefore, a new treatment method for depression therapy can be developed by regulating the exercise activity.

A combination of routine blood analytes predicts fitness decrement in elderly endurance athletes

Endurance sports are enjoying greater popularity, particularly among new target groups such as the elderly. Predictors of future physical capacities providing a basis for training adaptations are in high demand. We therefore aimed to estimate the future physical performance of elderly marathoners (runners/bicyclists) using a set of easily accessible standard laboratory parameters. To this end, 47 elderly marathon athletes underwent physical examinations including bicycle ergometry and a blood draw at baseline and after a three-year follow-up period. In order to compile a statistical model containing baseline laboratory results allowing prediction of follow-up ergometry performance, the cohort was subgrouped into a model training (n = 25) and a test sample (n = 22). The model containing significant predictors in univariate analysis (alanine aminotransferase, urea, folic acid, myeloperoxidase and total cholesterol) presented with high statistical significance and excellent goodness of fit (R2 = 0.789, ROC-AUC = 0.951±0.050) in the model training sample and was validated in the test sample (ROC-AUC = 0.786±0.098). Our results suggest that standard laboratory parameters could be particularly useful for predicting future physical capacity in elderly marathoners. It hence merits further research whether these conclusions can be translated to other disciplines or age groups.

A genetic risk factor for major depression and suicidal ideation is mitigated by physical activity

We evaluated associations of five candidate polymorphisms (Bcl1 [rs41423247], -2C/G [rs2070951], COMT [rs737865], Val66Met [rs6265], and 5HTTLPR [biallelic and triallelic [5HTTLPR/rs25531]) with probable MDD and suicidal ideation (SI), the effects of physical activity on these endpoints, and whether physical activity attenuates genetic risk in military members (N=736). C carriers who were also less physically active were 3.3 times as likely to meet criteria for probable MDD and 9.6 times as likely to endorse SI as compared to physically active GG carriers. An adequate dose of physical activity diminishes risk of MDD and SI imposed by a genetic predisposition.

Low Vitamin D Levels Do Not Predict Hyperglycemia in Elderly Endurance Athletes (but in Controls)

BACKGROUND AND AIM

Recent studies revealed a link between hypovitaminosis D3 and the risk for hyperglycemia. Further mechanistic and interventional investigations suggested a common reason for both conditions rather than a causal relationship. Exposure to sunlight is the most relevant source of vitamin D3 (25(OH)D), whereas adipose tissue is able to store relevant amounts of the lipophilic vitamin. Since running/bicycling leads to increased out-door time and alters physiological response mechanisms, it can be hypothesized that the correlation between hypovitaminosis D3 and hyperglycemia might be disturbed in outdoor athletes.

METHODS

47 elderly marathoners/bicyclists and 47 age/sex matched controls were studied in a longitudinal setting at baseline and after three years. HbA1c as a surrogate for (pre-)diabetic states was quantified via HPLC, 25(OH)D levels were measured by means of chemiluminescent assays. Physical performance was assessed by ergometry.

RESULTS

When adjusted for seasonal variations, 25(OH)D was significantly higher in athletes than in controls. 25(OH)D levels inversely correlated with triglycerides in both groups, whereas only in controls an association between high BMI or low physical performance with hypovitaminosis D3 had been found. Likewise, the presence of hypovitaminosis D3 at baseline successfully predicted hyperglycemia at the follow up examinations within the control group (AUC = 0.85, 95% CI [0.74, 0.96], p < .001, statistically independent from BMI), but not in athletes.

CONCLUSION

Our data suggest that mechanisms of HbA1c elevation might differ between athletes and controls. Thus, intense physical activity must be taken into account as a potential pre-analytic confounder when it is aimed to predict metabolic risk by vitamin D3 levels.

The current state of physical activity and exercise programs in German-speaking, Swiss psychiatric hospitals: results from a brief online survey

BACKGROUND

Physical activity and exercise programs (PAEPs) are an important factor in increasing and maintaining physical and mental health. This holds particularly true for patients with psychiatric disorders undergoing treatment in a psychiatric hospital. To understand whether the benefits reported in the literature are mirrored in current treatment modalities, the aim of the present study was to assess the current state of PAEPs in psychiatric hospitals in the German-speaking part of Switzerland.

METHODS

All psychiatric hospitals (N=55) in the German-speaking part of Switzerland were contacted in spring 2014. Staff responsible for PAEPs were asked to complete an online questionnaire covering questions related to PAEPs such as type, frequency, staff training, treatment rationale, importance of PAEPs within the treatment strategy, and possible avenues to increase PAEPs.

RESULTS

Staff members of 48 different psychiatric hospitals completed the survey. Hospitals provided the following therapeutic treatments: relaxation techniques (100%), sports therapy (97%), activity-related psychotherapeutic interventions (95%), physiotherapy (85%), body therapies (59%), far-east techniques (57%), and hippotherapy (22%). Frequencies ranged from once/week to five times/week. Approximately 25% of patients participated in the PAEPs. Interventions were offered irrespective of psychiatric disorders. PAEP providers wanted and needed more vocational training.

CONCLUSION

All participating psychiatric hospitals offer a broad variety of PAEPs in their treatment curricula. However, the majority of inpatients do not participate in PAEPs. Furthermore, those who do participate cannot continue to do so following discharge. PAEP providers need specific extended vocational trainings and believe that the potential of PA should be improved.

Conclusions about interventions, programs, and approaches for improving executive functions that appear justified and those that, despite much hype, do not

The ‘Executive Functions’ (EFs) of inhibitory control, working memory, and cognitive flexibility enable us to think before we act, resist temptations or impulsive reactions, stay focused, reason, problem-solve, flexibly adjust to changed demands or priorities, and see things from new and different perspectives. These skills are critical for success in all life's aspects and are sometimes more predictive than even IQ or socioeconomic status. Understandably, there is great interest in improving EFs. It's now clear they can be improved at any age through training and practice, much as physical exercise hones physical fitness. However, despite claims to the contrary, wide transfer does not seem to occur and ‘mindless’ aerobic exercise does little to improve EFs. Important questions remain: How much can EFs be improved (are benefits only superficial) and how long can benefits be sustained? What are the best methods for improving EFs? What about an approach accounts for its success? Do the answers to these differ by individual characteristics such as age or gender? Since stress, sadness, loneliness, or poor health impair EFs, and the reverse enhances EFs, we predict that besides directly train EFs, the most successful approaches for improving EFs will also address emotional, social, and physical needs.