The global prevalence of mental illnesses, including anxiety and depression disorders, continues to rise and sedentary behaviors become more common. This co-occurrence is concerning because physical activity is an established protective factor for anxiety and depressive symptoms. A reduced motivation to be physically active due to poor mental health, and a worsening of mental health due to reduced activity, represent a potential vicious cycle.We propose that cerebral oxygenation and aerobic energy metabolism may be at the core of the relationship between poor mental health and benefits conferred on mental health by physical activity. We discuss the role of regular physical activity in counteracting deficits in oxidative processes, but also of cognitive, anxiety and depressive symptoms. Moreover, we evaluate a complementary approach to specifically improve oxygen delivery and metabolism in the brain: therapeutic mild hypoxia.In summary, we attempt to provide an integrated assessment of how different types of physical activity and mild hypoxia interventions may be combined to synergistically improve different aspects of oxygen transport and utilization, thereby likely improving mental health. In addition, we highlight mental health-related risks of overwhelming the adaptive and metabolic capacities of the brain.
Background While low physical activity and depressive symptoms in older adults form a vicious cycle, their exact causal nature remains unclear due to a reliance on associational models. This study quantifies the reciprocal causal effects causal effects between physical activity levels and depressive symptoms among older European adults. Methods We analyzed multi-wave longitudinal data from the SHARE-ERIC database. To evaluate this reciprocal relationship, we applied advanced causal inference methods using Longitudinal Modified Treatment Policies (LMTP). This allowed us to estimate the causal impact of hypothetical static (i.e., all individuals are set to the same exposure level in a binary contrast) and dynamic shift scenarios (e.g., increasing physical activity levels or reducing depressive symptoms) while rigorously accounting for time-varying confounding. Results Increasing physical activity levels was associated with a significant reduction in subsequent depressive symptoms (23% reduction in the static scenario, MR = 0.714; 12% reduction per one-level shift, MR = 0.875). Conversely, reducing depressive symptoms predicted an improvement in physical activity participation (10% in the static scenario, MR = 0.898; 2-7% in the shift scenarios, MRs: 0.977-0.926). Subgroup analyses revealed that the protective effect of physical activity on depressive symptoms was more pronounced among individuals without existing illnesses (p = 0.002) and those not receiving therapies (p < 0.001). Similarly, the reverse effect (depressive symptoms on physical activity) was more pronounced among older adults (>= 75 years), and individuals with poor self-reported health, activity limitations, and multimorbidity (>= 3 chronic conditions). Conclusion These findings support a reciprocal relationship between physical activity levels and depressive symptoms in older adults. Under the stated assumptions, the magnitude of these causal effects varies significantly depending on individual health profiles and demographic characteristics. Therefore, rather than adopting a one-size-fits-all approach, interventions targeting physical activity and depressive symptoms should be tailored to the specific profiles of different subgroups
The inclusion of physical exercise in clinical practice guidelines (CPGs) for the treatment of depression in adults has come about due to evidence of the benefits of such exercise on the symptoms of depression. However, its use is not widespread amongst professionals due to a lack of resources and even a lack of specific training in this area. In this regard, the aim of this study is to examine the recommendations regarding the use of physical activity (PA) for the treatment of depression in adults, as set out in clinical practice guidelines published by internationally recognised organisations. To this end, a systematic review was carried out using the PRISMA method, in which 14 CPGs were identified and analysed. The results reveal that 10 of the 14 guidelines contain recommendations in favour of using PA as a complementary or adjunct to psychotherapeutic and/or pharmacological treatment, or as monotherapy for mild depression. Recommendations for PA were also found in all 14 guidelines for the different degrees of depression (mild, moderate or severe). Among the effects of PA on depression, a reduction in depressive symptoms and an improvement in general well-being and quality of life are described. In conclusion, this review supports the use of PA for the treatment of depression in the adult population.
