Impact of Trauma, Urbanicity, and Paternal Age on Theory of Mind in Schizophrenia

Objective: This study investigates the impact of specific environmental risk factors—namely childhood trauma, urbanicity, and advanced paternal age—on Theory of Mind (ToM) impairments in patients with schizophrenia. Specifically, we aimed to disentangle whether ToM deficits are solely intrinsic to the disorder or modulated by trauma history. Methods: A total of 54 patients with schizophrenia and 37 healthy controls were assessed in this cross-sectional study. Participants completed the Childhood Trauma Questionnaire (CTQ) and a battery of ToM tasks, including the Reading the Mind in the Eyes Test (RMET) and the Dokuz Eylul Theory of Mind Scale (DEZIKO). Patients were stratified into "High Trauma" (CTQ > 35) and "Low Trauma" (CTQ ≤ 35) groups to analyze the distinct contribution of trauma. Results: While patients generally exhibited poorer ToM performance compared to controls (RMET: p<0.001; DEZIKO: p<0.001), subgroup analyses revealed a crucial distinction. High-Trauma patients scored significantly lower than controls on both RMET (p=0.006) and DEZIKO Total (p=0.026). Importantly, Low-Trauma patients did not differ significantly from healthy controls (RMET: p>0.05; DEZIKO: p>0.05). Regarding specific environmental factors, patients residing in urban areas showed higher RMET scores compared to rural residents (Mean: 20.73 vs. 17.81; p=0.011). Conversely, advanced paternal age (≥35 years) was associated with significantly poorer performance on the faux pas recognition task (p=0.015). Conclusion: Our findings suggest that ToM deficits in schizophrenia may not be uniform but are significantly exacerbated by environmental insults, particularly childhood trauma. This challenges the view of ToM solely as a trait marker and highlights the importance of trauma-informed interventions. Future longitudinal studies should clarify these causal pathways to tailor cognitive remediation strategies.