Naturalistic Study of Ketamine in the Treatment of Depression

Mood disorders are chronic, recurrent, and highly prevalent health conditions worldwide. Major depression and bipolar disorder are often associated with psychosocial functional impairments and general medical conditions. Furthermore, suicide figures as one of the most important negative outcomes of mood disorders. In this sense, according to the World Health Organization (WHO), psychiatric disorders are associated with more than 90% of cases of complete suicide and are responsible for 30% of reported suicide cases worldwide. Suicide is a matter of concern for clinicians, not only because of the individual and familiar impact but also due to its social and population impact; then, research involving new potential treatments for suicide behavior ate highly needed. The literature has shown that ketamine, a substance commonly used as an anesthetic, is effective in treating depressive symptoms. Considering the high rate of suicide among patients with mood disorders and its consequences, the aim of this naturalistic study is to investigate the effect of ketamine in reducing the risk of suicide in patients with a depressive episode. The hypothesis is that treatment with ketamine will result in an improvement in depressive symptoms as well as in a decrease in the risk of suicide. Therefore, forty-five patients will be recruited, with major depressive disorder, bipolar I disorder or bipolar II disorder and who were already on ketamine treatment prescribed by assistant psychiatrist (inclusion criteria). Patients will go on the standard protocol of ketamine 0.5mg/kg subcutaneously (SC) twice a week for one month in general. In line with a naturalistic approach, all changes in the protocol, in time and doses will be accepted, according to the assistant doctor prescription without study intervention. After this period, they could receive the same dose of the medication once a week for the third month. In addition, patients will be monitored by phone until month six. Forty-five participants without any personal or first-degree family history of psychiatry or neurologic disorders will be recruited to participate as controls. Biochemical analyses will be used to investigate inflammatory markers, transcription factors and other peripheral biomarkers in patients with mood disorders and healthy controls.