A nation-wide twin study of social cognition in schizophrenia spectrum disorders

Cecilie K Lemvigh,Birte Y Glenthøj,Birgitte Fagerlund

doi:10.1038/s41537-022-00223-1

Abstract

We examined social cognition in 32 monozygotic (MZ) and 21 dizygotic (DZ) twin pairs concordant or discordant for a schizophrenia spectrum diagnosis and healthy control (HC) twin pairs (29 MZ/20 DZ). All participants were recruited through the Danish registers. Patients showed several deficits in the ability to detect sarcasm. Impairments were also observed in the unaffected MZ co-twins, indicating that social cognitive deficits could be a genetic vulnerability indicator of the disease. Worse social cognition was associated with lower intelligence and higher levels of psychopathology in patients.

Highlights

Social cognitive deficits are a well-established finding in patients with schizophrenia and these deficits are strongly related to functional outcome[1]
Patients performed worse than healthy control (HC) in both the simple, U = 2378.5, p = 0.020, r = −0.18, and paradoxical sarcastic conditions, U = 2073.0, p < 0.001, r = −0.28, only the difference in paradoxical sarcasm remained significant after correction for multiple comparisons
The unaffected co-twins performed similar to HCs in the sincere, U = 2252.5, p = 0.176, r = −0.11, and simple sarcastic conditions, U = 2384.0, p = 0.401, r = −0.07, while a significant group difference was observed in the paradoxical sarcastic condition, U = 2040.5, p = 0.022, r = −0.17, but this did not survive false discovery rate (FDR) corrections

Summary

Introduction

Social cognitive deficits are a well-established finding in patients with schizophrenia and these deficits are strongly related to functional outcome[1]. One example of a social cognitive function that is impaired in patients with schizophrenia is the ability to detect sarcasm[2,3]. The ability to detect sarcasm requires intact theory of mind[4,5] as well as social perception[6], i.e. the processes involved in making inferences about complex/ambiguous social situations using verbal or non-verbal cues, with impairments resulting in misinterpretations of the intent of others[7]. Social cognition is impaired in first-degree relatives of patients with schizophrenia, suggesting that these deficits may be related to the genetic vulnerability of the disorder[8]. Previous twin studies have established that most cognitive functions are strongly influenced by genetics[9] and show genetic overlap with schizophrenia liability, indicating that shared genetic factors influence cognition and schizophrenia risk[10–12]. Twin studies of social cognition in schizophrenia are lacking[9,13]

Methods

Results

Conclusion