Background and Hypothesis

Some of the most debilitating aspects of schizophrenia and other serious mental illnesses (SMI) are the impairments in social perception, motivation, and behavior that frequently accompany these conditions. These impairments may ultimately lead to chronic social disconnection (ie, social withdrawal, objective isolation, and perceived social isolation or loneliness), which may contribute to the poor cardiometabolic health and early mortality commonly observed in SMI. However, the psychological and neurobiological mechanisms underlying relationships between impairments in social perception and motivation and social isolation and loneliness in SMI remain incompletely understood.

Study Design

A narrative, selective review of studies on social withdrawal, isolation, loneliness, and health in SMI.

Study Results

We describe some of what is known and hypothesized about the psychological and neurobiological mechanisms of social disconnection in the general population, and how these mechanisms may contribute to social isolation and loneliness, and their consequences, in individuals with SMI.


A synthesis of evolutionary and cognitive theories with the “social homeostasis” model of social isolation and loneliness represents one testable framework for understanding the dynamic cognitive and biological correlates, as well as the health consequences, of social disconnection in SMI. The development of such an understanding may provide the basis for novel approaches for preventing or treating both functional disability and poor physical health that diminish the quality and length of life for many individuals with these conditions.

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