Inflammation and depression in patients with autoimmune disease, diabetes, and obesity

Depression presents frequently in patients with inflammatory illnesses. Inflammation is increasingly recognized as a pathoetiologic factor in the development of depressive symptoms. Increased prevalence and incidence of depression has been observed in patients with autoimmune disease, including inflammatory bowel disease, rheumatoid arthritis, psoriasis, systemic lupus erythematosus, and multiple sclerosis. Metabolic disorders associated with inflammation, such as obesity or diabetes, are also associated with increased prevalence and incidence of depression. Indicators of disease activity or increased inflammation are associated with worsened depressive symptomatology in these diseases. Depression concurrently increases the risk of developing autoimmune disease, diabetes, and obesity, suggesting a bidirectional relationship. Depression worsens prognosis and is often undertreated in these diseases. Emerging evidence suggests that disease-specific antiinflammatory treatments (such as biologics for autoimmune disease or bariatric surgery for obesity) can specifically target depressive symptoms in inflammatory illnesses.