section_path: Health effects/Neurobiological/Depression
section_name: Depression
paragraph_text: Depression
  
  A number of medical reviews have indicated that exercise has a marked and persistent antidepressant effect in humans, an effect believed to be mediated through enhanced BDNF signaling in the brain. Several systematic reviews have analyzed the potential for physical exercise in the treatment of depressive disorders. The 2013 Cochrane Collaboration review on physical exercise for depression noted that, based upon limited evidence, it is more effective than a control intervention and comparable to psychological or antidepressant drug therapies. Three subsequent 2014 systematic reviews that included the Cochrane review in their analysis concluded with similar findings: one indicated that physical exercise is effective as an adjunct treatment (i.e., treatments that are used together) with antidepressant medication; the other two indicated that physical exercise has marked antidepressant effects and recommended the inclusion of physical activity as an adjunct treatment for mild–moderate depression and mental illness in general. One systematic review noted that yoga may be effective in alleviating symptoms of prenatal depression. Another review asserted that evidence from clinical trials supports the efficacy of physical exercise as a treatment for depression over a 2–4 month period. These benefits have also been noted in old age, with a review conducted in 2019 finding that exercise is an effective treatment for clinically diagnosed depression in older adults.
  
  Continuous aerobic exercise can induce a transient state of euphoria, colloquially known as a "runner's high" in distance running or a "rower's high" in crew, through the increased biosynthesis of at least three euphoriant neurochemicals: anandamide (an endocannabinoid), β-endorphin (an endogenous opioid), and phenethylamine (a trace amine and amphetamine analog).