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.

Trustworthiness judgments and pupil-size in individuals with schizophrenia.

Individuals with schizophrenia show aberrant processing of social cues. In the current study, we (1) compared trustworthiness ratings of faces between patients with schizophrenia and healthy controls, (2) compared pupillary reactivity between patients and controls (3) examined whether trustworthiness judgments in schizophrenia are related to pupil reactivity, (4) and examined associations between trustworthiness judgements and symptom severity, specifically paranoia. Patients with schizophrenia spectrum disorders (N = 48) and healthy controls (N = 33) completed a Trustworthiness Task, during which their pupil size was measured via an eye-tracking device. The mean baseline-corrected pupil size was calculated from 24 pictures of real neutral faces, each presented for 2500 ms. Self-reported psychotic experiences were measured by Community Assessment of Psychic Functioning (CAPE-42), and symptom severity was rated by Brief Psychiatric Rating Scale (BPRS). No group differences were found in trustworthiness ratings or pupil reactivity parameters during trustworthiness judgments. Separately, among patients, absolute difference in pupil-size change and dilation after reaching minimum size were related to more severe positive symptoms and self-reported paranoia. Our results did not show social cognitive biases in the stable outpatients with schizophrenia, or the role of pupil reactivity in trustworthiness judgments. Future studies should use longer stimuli for pupillary reactivity and control the type and dosage of utilized antipsychotic medication. Further studies are required to explore relationships in larger and more symptomatic groups of patients.

Connections between and within extended psychosis and autistic phenotypes and social relationships in the general population.

OBJECTIVES: Non - clinical individuals with higher levels of autistic traits and psychotic experiences also have problems in social relationships. Therefore, this study aimed to model complex associations between autistic and psychotic phenotypes and indicators of social relationships in the general population using a network approach. METHODS: The sample consisted of 649 participants with a mean age of M = 40.23 and SD = 13.09 sampled from the general population. The sample was representative for the 18-65 years old general population in the Slovak Republic. The following scales were administered: Community Assessment of Psychic Experiences, The Comprehensive Autistic Trait Inventory, and NIH Toolbox Adult Social Relationship Scales. Associations between variables and the presence of communities were identified using Exploratory Graph Analysis. RESULTS: Results revealed four highly stable and densely connected communities within the network: social relationships, autistic traits, positive symptoms, and the last one consisting of all negative symptoms, problems in social interactions, and depression. The most important variables in the network were difficulties in social interaction, perceived rejection, bizarre ideas, depression, and social withdrawal. CONCLUSIONS: The psychotic and autistic phenotypes in the general population showed a network of connections with characteristics of social relationships. Community detection revealed that autistic traits and psychotic-like experiences formed relatively independent communities. Further, there was substantial overlap between negative symptoms (e.g., social withdrawal), and core features of the autistic phenotype, especially social interaction difficulties.