Etiopathogenesis of depression and experimental depression models used in preclinical studies

Abstract

Depression is the most frequent psychiatric illness among mood disorders, affecting approximately 10% of adults. Especially recurrent and moderate/severe depression can become a serious public health problem by impairing people’s life quality. The monoamine hypothesis is the most widely accepted hypothesis for clarifying the pathophysiology of depression. Depression’s pathogenesis and etiology, however, are still poorly understood. Tricyclic antidepressants, monoamine oxidase inhibitors, selective serotonin or noradrenaline reuptake inhibitors, different atypical antidepressants, and electroconvulsive therapy are currently available therapies for depression. Although these treatment options are effective, a large number of patients do not respond to treatment or do not attain long-term remission. Furthermore, present antidepressants used in clinics have disadvantages such as delayed onset of effects, side effects, and patient compliance problems. Therefore, the discovery of new antidepressant medications is crucial. Animal models are critical in investigating the etiology of depression and developing novel treatments. Hence, in this review, the main mechanisms involved in the etiopathogenesis of depression and the experimental depression models used in preclinical studies have been demonstrated.