Recent studies have revealed that inflammation, among other factors, may be involved in the pathogenesis of depression. One line of studies has shown that depression is frequently associated with manifest gastrointestinal inflammations and autoimmune diseases as well as with cardiovascular diseases, neurodegenerative diseases, type 2-diabetes and also cancer, in which chronic low-grade inflammation is a significant contributing factor. Thus depression may be a neuropsychiatric manifestation of a chronic inflammatory syndrome. Another line of studies has shown that the primary cause of inflammation may be the dysfunction of the "gut-brain axis". Although, this is a bidirectional mechanism, life style factors may primarily affect the symbiosis between host mucous membrane and the microbiota. Local inflammation through the release of cytokines, neuropeptides and eicosanoids may also influence the function of the brain and of other organs. Role of metabolic burst due to inflammation represents a new aspect in both pathophysiology and treatment of the depression. Finally, an increasing number of clinical studies have shown that treating gastrointestinal inflammations with probiotics, vitamin B, D and omega 3 fatty acids, through attenuating proinflammatory stimuli to brain, may also improve depression symptoms and quality of life. All these findings justify an assumption that treating gastrointestinal inflammations may improve the efficacy of the currently used treatment modalities of depression and related diseases. However, further studies are certainly needed to confirm these findings.