Untangling violent behavior in schizophrenia: The role of formal thought disorder and cognitive dysfunction

Violent offending in schizophrenia has been linked to psychopathology, cognitive dysfunction, and formal thought disorder; however, their combined contribution remains unclear. This study examined the relationships between formal thought disorder, executive functions, and violent offending in individuals with schizophrenia.

This cross-sectional study included 64 individuals with schizophrenia and a documented history of violent offending and 64 clinical controls without forensic history. Participants were assessed using the Positive and Negative Syndrome Scale, the Thought and Language Disorder Scale, the Buss-Perry Aggression Questionnaire, and the Frontal Assessment Battery. Group comparisons were conducted, followed by multivariable logistic regression and structural equation modelling to examine direct and indirect associations with violent offending.

Violent offenders showed significantly higher total formal thought disorder scores (p < 0.001), greater overall symptom severity (p < 0.001), higher negative (p = 0.004) and general psychopathology scores (p = 0.003), and longer durations of untreated psychosis (p = 0.038). Executive functions did not differ significantly between groups. Logistic regression identified objective positive and subjective negative thought disorder as significant positive predictors of violent offending, whereas greater positive symptom severity was associated with reduced risk. Structural equation modelling indicated that executive dysfunction was associated with thought disorder dimensions, with objective positive thought disorder showing a direct association with violent offending.

Formal thought disorder is closely associated with violent offending in schizophrenia, while executive dysfunction may contribute indirectly through its relationship with thought disorganization, highlighting the importance of detailed thought disorder assessment in violence risk evaluation.