Psychosis and conduct disorder in Greek forensic patients found not guilty by reason of insanity: Differences between patients with and those without a history of conduct disorder in childhood or adolescence

Much epidemiological evidence converges in identifying distinct types of individuals suffering from schizophrenia who exhibit aggressive behavior: those with and those without a history of conduct disorder (CD) in childhood or adolescence. In this study a sample of Greek forensic patients suffering from psychotic disorders was examined regarding demographic, clinical, legal and psychometric characteristics. All patients had committed a crime and were found not guilty by reason of insanity (NGRIs) in a court of law. This study aims to clarify whether history of conduct disorder leads to greater violence or shapes the index offense in some way. It also aims to examine new parameters, such as psychopathology, personality traits, substance abuse and risk assessment, not included in the relevant literature so far, and whether they are relevant and why in this specific group of patients. The sample was divided in two groups depending on the history of CD or not, and subsequently statistically significant differences were explored between the groups. The research aimed to highlight specific characteristics of both groups with the ultimate goal of making more accurate prognosis regarding risk assessment, as well as determining different needs for treatment in each group (e.g. drug abuse). Overall, 78 forensic psychiatric records of NGRI offenders were identified throughout a five-year period in the Psychiatric Hospital of Thessaloniki (January 2015 to January 2020), who were divided into two groups depending on the history of conduct disorder in childhood or adolescence (N = 30) or not (N = 48). The two groups were compared regarding hostility and aggression (with the Hostility and Direction of Hostility Questionnaire-HDHQ and the Aggression Questionnaire), personality traits (with the Zuckerman- Kuhlman Personality Questionnaire-ZKPQ), dangerousness (with the Historical, Clinical and Risk Management 20- HCR-20 scale), addiction (with the Addiction Severity Index-ASI), previous violent behavior or convictions (with a semi-structured tool), and psychopathology current and at the time of the index (with the Positive And Negative Syndrome Scale-PANSS). Comparing the two groups (with CD history vs. without CD history) we found that patients with a history of conduct disorder had significantly higher compulsory hospitalization rates up to the time of the perpetration of the offense and a significantly higher rate of illicit drug use. While they were more likely to exhibit violent behavior before the index offense, it was noted that they committed fewer crimes against life. They were younger at the index offense and they presented with more severe positive symptomatology at the time of the research and a steadily high risk assessment score. Our findings underline the importance of diagnosing CD in early life and subsequently raising awareness when this individual develops schizophrenic disorder, thus emphasizing the need for appropriately targeted interventions in each case. Our research also illustrates that forensic patients with both schizophrenia and a history of conduct disorder before the age of 15 exhibit more severe psychopathology after the index crime even after long hospitalization and treatment. Our findings illustrate that the diagnosis of CD in psychotic offenders found not guilty by reason of insanity affects their dangerousness in general, but not the severity of the crimes committed.