Exercise-Induced Brain-Derived Neurotrophic Factor as a Mediator of Antidepressant Effects: A Narrative Review

Depression represents a significant global public health problem, negatively affecting patients’ quality of life and social functioning. Despite the increasing availability of effective pharmacological and psychotherapeutic interventions, a substantial proportion of patients fail to achieve full symptom remission. [1] Recently, growing attention has been directed toward physical activity as a non-pharmacological approach supporting the treatment of depression. Multiple studies indicate that regular exercise may lead to a reduction in depressive symptoms and improvements in cognitive function. In addition, other non-pharmacological interventions, including probiotics [2], meditation, light therapy [3,4], and physical training, have been investigated for their potential antidepressant effects. One of the proposed mechanisms underlying the beneficial effects of physical activity, apart from its anti-inflammatory properties and stimulation of endorphin release, is the modulation of brain-derived neurotrophic factor (BDNF) expression. BDNF plays a crucial role in neuroplasticity, neurogenesis, and the regulation of synaptic function, particularly within the hippocampus, as well as in the spinal cord and peripheral nervous system. [5,6] The aim of this narrative review is to summarize and critically discuss current evidence on the effects of physical activity on BDNF levels and its role in antidepressant mechanisms, highlighting its potential clinical relevance in the management of depressive disorders.