RNA Interference: A New Hope in Understanding and Treatment of Psychiatric Disorders

Abstract

The prevalence and global burden of mental disorders are high. The number of years lost due to disability they cause, has major impact both on the individual and the society. Unlike the classification of other medical problems that are based on the etiology, psychiatric disorders are defined phenomenologically, thus treatments do not address the etiology of the disorders. Moreover the onset of action of the present treatment options takes time and treatment resistance is a major issue in the management of psychiatric patients. Understanding the etiology and psychopathological processes underlying the mental disorders would help to develop new treatment strategies and options for these disorders. There are several studies investigating the neurobiology of mental disorders from various aspects. The discovery of RNA interference, a new technique, has led to excitement and innovating scientist was awarded by Nobel Prize in Medicine in 2006, as it has overcome the limitations of previous techniques. RNA interference technique is used to decrease the mRNA expression of target genes by means of double stranded small RNA molecules complimentary to the target gene. These small RNA molecules can be administered into the cells exogenously by different ways, for instance they can be coupled to plasmids or transfection reagents. Besides its exogenous use as a research tool to suppress gene expression, RNA interference is an endogenous process that the organisms use for functions like the control of viruses and mobile genetic elements. Besides being used for research in other medical disciplines, RNA interference has become the preferred method in psychiatric research. It yields to understanding of many molecules that play role in the neurobiology of mood, anxiety, and substance use disorders and results in identification of new treatment targets. This technique enables researchers to evaluate candidate genes quickly that were identifed in previous studies and were thought to be important in the neurobiology of psychiatric disorders. In this paper, we review RNA interference and the studies that used this technique to investigate the neurobiology of mood, anxiety, and substance use disorders.