Experimental Models of Depression

Abstract

Depression is the most common disease among psychiatric disorders. Depression with anhedonia may lead to a weakening of social communication, an intense feeling of sadness, or it can lead to suicide. It has been observed that people who become depressed as a result of environmental factors outnumber people genetically prone to depression. One of the most important factors for depression is found as stress. As a result of stress, cortisol is secreted in our body. In prolonged stress situations, it has been observed that excessive secretion of cortisol causes depression in the prefrontal lobe. Based on this information, the application of experimental animal models are prominent in order to better understand the pathophysiology of the disease and to develop various treatments. Because of the importance of stress in depression, most of experimental animal models were created by exposing them under stress. The basis of all models is to expose the animal to a forced stress. And as a result, the animal is expected to imitate depression-like behaviors. In this review, alternative depression models such as chronic mild stress, learned helplessness, social stress, early life stress, olfactory bulbectomy and corticosteroid administration that can be used to create models of depression. In addition to the evaluation of animals using these models, forced swimming, which can be used to determine whether the animal is depressed or not as well as the tests such as tail hanging are included. These tests are based on the behavioral helplessness. In addition, validity criteria are very important in experimental depression models. Validity is chosen according to the goals of the model and can be tested in different ways.

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

The authors received no financial support for the research and/or authorship of this article.