Do clinical features relate to theory of mind, empathy and 2D:4D in schizophrenia?

Abstract

OBJECTIVE: Digit ratios may be accepted as an indicator of level of prenatal androgen exposure during the fetal developmental period. Female-typical digit ratios have been suggested to be associated with better mentalizing and empathic abilities in general population. Recently, a number of studies have investigated the ratio of hand’s second and fourth digit fingers (2D:4D) in schizophrenia. The aim of this study was to investigate the hypothesis that positive symptoms are related to female-biased 2D:4D and relatively less impaired social cognition in schizophrenia, negative dimension is related to male-biased 2D:4D ratio and more pronounced deficits in social cognition. METHOD: The study was carried out in 48 patients with schizophrenia and 48 healthy controls. Patients were evaluated by Positive and Negative Syndrome Scale (PANSS). A digital caliper was used to measure 2D:4D finger lengths and social cognitive abilities were assessed using the Empathy Quotient (EQ) test and Reading Mind in the Eyes Test (RMET). RESULTS: Patients with schizophrenia had increased left 2D:4D finger lengths and showed poor theory of mind (ToM) and empathic abilities compared to healthy controls (p < 0.05). It was found that negative symptoms but not male-biased 2D:4D ratio were significantly associated with impaired RMET performance (p < 0.05). CONCLUSION: The present study indicates that negative dimension is negatively related to the severity of deficits in social cognition in schizophrenia. There was no evidence for a significant effect of sexual dimorphism as measured by digit ratio on social cognition and symptoms in schizophrenia.

Keywords

• Anthropometry
• empathy
• schizophrenia
• symptoms
• theory of mind