Paliperidone and Lithium in the Treatment of Suicidality - Treatment Indication and Epigenetic Regulation

Specific Aim 1: The atypical antipsychotic, paliperidone, when initiated simultaneously with an antidepressant, is superior to lithium plus antidepressant in the early intervention of suicidality in patients with Major Depressive Disorder (MDD). The goal of this aim is to examine the clinical efficacy of paliperidone in reducing suicidality, with a focus on early intervention. The hypothesis is based on our recently completed pilot study in which we found that the atypical antipsychotic, risperidone, had a rapid onset of action to reduce suicidality in patients with MDD. In view of a shortage in acute pharmacological management of suicidality, this study will provide an important new treatment option for the life threatening psychiatric condition. Specific Aim 2: Both paliperidone and lithium regulate epigenetics by stabilizing DNA methylation, which is correlated with inhibition of glycogen synthase kinase-3 (GSK3) activity and improved clinical symptoms. This exploratory aim is developed based on the recent findings that DNA methylation is involved in regulation of mood, behavior, and cognition, and the enzyme of this epigenetic mechanism - DNA methyltransferase-1 (DNMT1) is regulated by the therapeutic target Glycogen synthase kinase 3 (GSK3). We will measure the expression of DNMTs and DNA methylation of global DNA, Brain-derived neurotrophic factor (BDNF), and Tropomyosin receptor kinase B (TrkB) in peripheral blood before and after study drug treatment, and analyze their correlation with GSK3 activity and clinical symptoms in response to treatment. Outcomes from this study will provide important new information in future development of more effective treatment options for suicidality targeting epigenetic regulation.