Comparison of delusional disorder and schizophrenia in cases lacking criminal responsibility: Sociodemographic, clinical and offense-related characteristics.

Criminal responsibility can be significantly impaired by psychotic disorders. Although delusional disorder (DD) is classified within the schizophrenia spectrum, it clinically differs from schizophrenia (SCH) in age at onset, functional level, and symptom profile. This retrospective study examined differences in sociodemographic, clinical, and criminal characteristics between DD and SCH cases adjudicated as completely lacking criminal responsibility under Article 32/1 of the Turkish Penal Code. A total of 387 cases evaluated by the Council of Forensic Medicine between 2019 and 2023 were reviewed. Statistical comparisons between the groups revealed that DD cases were diagnosed at a later age and exhibited fewer psychotic symptoms prior to the offense. The DD group also demonstrated higher marriage rates and more children. While victims in both groups were predominantly from the offenders' close social environments, offenses against spouses were significantly more frequent in DD, frequently occurring in the context of jealous delusions. Offense types also varied; verbal violence was more common in DD, whereas physical violence was more frequent in SCH. Conversely, SCH was characterized by earlier symptom onset, lower functional capacity, and more prominent positive symptoms. These associations, including spouse-directed offenses and verbal violence, persisted in logistic regression models adjusted for age at the time of the offense and sex. These findings indicate that DD and SCH present distinct clinical profiles and highlight the importance of considering diagnosis-specific clinical and offense-related patterns in forensic assessments.