Functional Role of Physical Exercise and Omega-3 Fatty Acids on Depression and Mood Disorders

In adulthood, depression is the most common psychiatric disorder and is projected to become the highest cause of disease burden by 2020. Major depression represents a debilitating condition that significantly impairs the function of the central nervous system and severely degrades the quality of life. Several hypotheses regarding the mechanisms that underlie the path physiology of major depression have been investigated. Indeed, major depression has a multifactorial etiology arising from environmental, psychological, genetic and biological factors. Research over the past decades has clarified that depression is mainly associated with neurotransmitter and neurotrophic factors imbalances, HPA disturbances, deregulated inflammatory pathways, increased oxidative damage, neurogenesis dysfunction and mitochondrial disturbances. In the recent years, the bulk of the research has concentrated on the study of the neurotransmitters, neurotrophins, neurogenesis and neuroinflammation as the main factors involved in the pathogenesis of depression. Since recent evidence has suggested that sedentary life and poor diet contribute to the genesis and course of depression (Berk et al., 2013), in this chapter we have taken into account the effects of physical exercise and nutritional factors crucial for the central nervous system, such as omega-3 fatty acids, on depression and mood disorders.