An analysis of hospital records combined with data from the Care Register for Health Care in Finland showed that individuals with high levels of psychopathic traits had a 9.3 times higher risk of developing schizophrenia compared to individuals with low levels of these traits. Individuals classified as psychopathic were 2.37 times more likely to develop schizophrenia compared to their non-psychopathic peers. The research was published in Acta Psychiatrica Scandinavica.
Psychopathic traits are a constellation of personality characteristics involving shallow emotional experience, reduced empathy, and limited remorse for harming others. Individuals high in these traits tend to show callousness, emotional detachment, and difficulty forming genuine interpersonal bonds. They may be superficially charming and socially assertive while lacking emotional depth.
Psychopathic traits also include manipulativeness, deceitfulness, and a tendency to exploit others for personal gain. Impulsivity and poor behavioral control are common, leading to risk-taking and rule-breaking behavior. Some individuals display chronic irresponsibility, failing to honor obligations in work, family, or social life. These traits exist on a continuum in the general population and are not limited to criminal or clinical groups. They tend to be stable over time.
Study author Olli Vaurio and his colleagues wanted to explore whether psychopathic traits are associated with an increased risk of developing schizophrenia later in life. They note that neuroimaging studies point to structural similarities between the brains of patients with schizophrenia and those with pronounced psychopathic traits. Many other studies also reported correlations between specific psychopathic traits and schizophrenia.
These researchers combined data from individuals who underwent forensic psychiatric evaluations at Niuvanniemi Hospital in Finland between 1984 and 1993 with records from the Care Register for Health Care. The Care Register for Health Care is a nationwide administrative database in Finland that systematically records information on inpatient and specialized outpatient health care visits, diagnoses, and treatments. They excluded individuals who were not criminally responsible, i.e., individuals with severe mental illness, intellectual disability, or organic psychotic disorders from analyses.
In total, the study included data from 341 individuals. 278 were males. Their average age was approximately 33.5 years. The Psychopathy Checklist-Revised (PCL-R) was used to assess psychopathic traits. The study authors divided participants into three groups based on their scores on the PCL-R – those with low, moderate, and high levels of psychopathic traits.
Results showed that, compared to participants with low levels of psychopathic traits, those with moderate traits had a 5.3 times higher risk of being hospitalized for schizophrenia, while the risk was 9.3 times higher for those with high levels of psychopathic traits. When looking at individuals classified as psychopathic and those not in that category, individuals classified as psychopathic were 2.37 times more likely to develop schizophrenia. 20% of individuals classified as psychopathic developed schizophrenia over the follow-up period.
“The novel results suggest that there is a link between higher PCL-R scores and a higher risk of later-life schizophrenia outbreak among non-psychotic individuals undergoing FPE [forensic psychiatric evaluations],” the study authors concluded.
The study contributes to the scientific understanding of the links between psychopathy and schizophrenia. However, it should be noted that the study was conducted on individuals undergoing forensic psychiatric evaluations, which are clinical assessments conducted to examine a person’s mental state in relation to legal standards. They are conducted exclusively by court order. As such, these individuals are not representative of the general population of people with mental health problems.
The paper, “Psychopathic Traits Associate With Later Schizophrenia,” was authored by Olli Vaurio, Jari Tiihonen, Markku Lähteenvuo, and Johannes Lieslehto.