Interpersonal distance in schizophrenia: A systematic review.

BACKGROUND AND HYPOTHESIS: Schizophrenia is often associated with severe difficulties in social functioning, resulting in increased isolation and subsequent loneliness. Interpersonal distance - the amount of space around an individual's body during social interaction - can signal such difficulties. However, little is known about how individuals with schizophrenia regulate their interpersonal distance during social encounters. Summarizing the current empirical findings of interpersonal distance regulation in schizophrenia can bring novel perspectives for understanding interpersonal difficulties observed in this clinical population.

STUDY DESIGN: This systematic review examined empirical studies indexed in Web of Science and PubMed based on a-priori-defined criteria. 1164 studies were screened with the final review consisting of 14 studies. They together included 1145 adult participants, of whom 668 were diagnosed with schizophrenia or psychotic disorder.

STUDY RESULTS: The studies clearly showed that patients maintain greater interpersonal distances than do controls. Furthermore, a larger distance was linked to more severe positive and negative symptoms. More specifically, the link to symptoms was more pronounced when patients were being approached by someone else during interactions. On a neurobiological level, the increased activity and functional connectivity of the dorsal inferior parietal sulcus and increased subjective state-dependent stress are further indicated as being potentially related to increase interpersonal distancing in schizophrenia.

CONCLUSIONS: We provided information about the aberrant modulation of interpersonal distance in schizophrenia. Studies showed substantial heterogeneity in tasks used to measure interpersonal distance. Future studies should look at links to social functioning, underlying neurobiology, and neuroendocrinal regulation of interpersonal space in schizophrenia.