New Approach for Treatment-Resistant Depression

Abstract

Depression is one of the major mental illnesses seen worldwide, which in some cases can result in suicide. Although different drugs and methods can be used for treatment, one-third of the patients show resistance to conventional treatments. Treatment-resistant depression (TRD) is defined as a condition where a patient shows a response rate of less than 25% to at least two adequate trials of antidepressants with distinct mechanisms of action. Research on the use of ketamine in such patients has been ongoing for more than 20 years. Ketamine is a dissociative anesthetic mainly used for the induction and maintenance of anesthesia for animals and humans. Ketamine’s routine clinical usage for depression treatment is limited due to its dissociative effects, alterations in sensory perception, intravenous route of administration, and abuse potential. These limitations have prompted researchers to investigate the precise mechanisms of action behind ketamine’s antidepressant clinical responses in order to better understand its key targets. One of the primary elements behind ketamine’s quick and strong antidepressant response is thought to be a brain-derived neurotrophic factor (BDNF)-mediated mechanism. Ketamine may help repair the neurobiological alterations associated with depression by restoring BDNF levels while stimulating neuroplasticity. This chapter aims to provide an overview of the existing literature regarding the relationship between antidepressant treatment and BDNF levels in depression. Understanding these mechanisms may contribute to the development of more targeted and effective treatments for depression and related disorders.