Theory of mind deficit in psychiatric disorders

Theory of mind (TOM) is a term which has interested many scientists for more than thirty years. Nowadays there are three streams of TOM research: metacognition, where TOM is defined as a representation of mental states of others; naive theory, focused on childish mentalistic abilities used to explain mental states of others; and social cognition, which refers to processing and making inferences about others' actions. Deficits in TOM have been shown in many psychiatric disorders. The past two decades have witnessed a shift in understanding and treatment of many mental illnesses, in view of which TOM is gaining high importance. In this paper TOM will be discussed from the cognitive, neurobiological and psychiatric perspective. Some researchers suggest that understanding neural correlates of TOM will enhance our understanding of its cognitive mechanisms. Hence the "TOM network" and differences in its activation in psychiatric disorders will be presented. Moreover, I will discuss research in the area of TOM in schizophrenia, depression, bipolar disorder and eating disorders. The present paper should be treated as a review of important studies (not exhausting all issues) which indicate directions for further research in functional architecture of TOM (here understood as a type of cognitive representation and cognitive processes involved in realizing these representations, as well as their interrelations) amongst people with different psychiatric disorders.