2024-11-0920210924-977X10.1016/j.euroneuro.2021.01.044http://dx.doi.org/10.1016/j.euroneuro.2021.01.044https://hdl.handle.net/20.500.14288/8947Background: Despite some risk factors for homicidal behavior have been shown in schizophrenia patients, these findings are generally obtained from retrospective research [1], [2], [3]. In our study, detailed sociodemographic, historical, and clinical characteristics, trait impulsivity, and trait aggression levels, and peripheral inflammatory markers were evaluated in patients with schizophrenia, and compared between homicidal and non-criminal groups. Characteristics of homicidal behavior in the homicidal group were identified as well as the descriptive characteristics of recidivists. Methods: The study population consisted of patients who had been diagnosed with schizophrenia according to the DSM-5 criteria and treating in either inpatient or outpatient units at Bakirkoy Prof. Mazhar Osman Training and Research Hospital for Psychiatry, Neurology, and Neurosurgery. Thirty-three schizophrenia patients who have allegedly committed homicide in the first degree and 39 patients with neither criminal history nor severe violent behavior in the past were enrolled. The data form included sociodemographic, historical, clinical, and forensic information. The patients were evaluated with the Positive and Negative Syndrome Scale (PANSS), Barratt Impulsivity Scale-11 (BIS-11), and the Buss-Warren Aggression Questionnairre (BWAQ), and inflammatory markers were calculated from the laboratory values which were routinely checked within the last month. Results: Compared to the non-criminal group, the education level and regular employment rate of the homicidal group is lower (p<0,05); lifetime alcohol use disorder (AUD) (p=0,001), childhood trauma (p<0,05), and the frequency of criminal history in the family (p<0,05) is higher. BIS-11 (p <0,001) and BWAQ (p<0,05) total scores were significantly higher in the homicidal group. C-reactive protein (CRP) (p<0,05), monocyte/lymphocyte ratio (MLR) (p<0,05), CRP/albumin ratio (CAR) (p<0,05), and monocyte/hemoglobin ratio (MHR) (p<0,05) were found to be significantly higher in the homicidal group. In a total of 39 homicide incidents, the victims were often family members (p<0,05), and the most frequent homicide method was the use of sharp instruments (p<0,001). It was observed that 35 of 39 homicidal incidents involved psychotic motivation, 59% of them had predominant impulsive behavior while 28% of them had predominant proactive behavior. Lifelong substance use disorder was predictive for recidivism. According to the logistic regression model, less than seven years of education, being unmarried, presence of lifelong AUD, BWAQ Hostility score greater than 23, and CAR higher than 1 significantly predicted homicide in schizophrenia. Conclusion: To reduce the risk of homicidal behavior in schizophrenia, it would be useful to employ interventions that increase social support and treatment compliance and decrease alcohol abuse as well as to develop risk assessment algorithms including sociodemographic factors such as education level, and psychometric assessment of trait impulsivity and trait aggression [4]. In our opinion, the findings of our study will inspire further studies that examine the motivation and qualities of homicidal behavior and investigate the relationship between the behavioral and biological substrates of violence and homicide.Clinical neuropsychologyNeurosciencesPharmacologyPharmacyPsychiatryThe neurobiology of homicidal behaviour in schizophrenia: association between inflammation, impulsivity, and aggressionMeeting Abstract1873-78626246081000369749