An assessment of personality disorders with the Five-Factor Model among Belgian inmates

Many international studies report a high prevalence of personality disorders among inmates on the basis of (semi)-structured diagnostic interviews. The present study proposes a self-reported evaluation of personality disorders using the NEO PI-R. The sample consists of 244 male and 18 female inmates (N=262) who were psychologically assessed. The analysis of the five psychological domains shows that the French-speaking Belgian inmates are as stable, as extroverted, more closed, more agreeable and more conscientious than the normative sample. The NEO PI-R facets are also analyzed. The mean Cohen's d (.26) is small. Two personality disorders have medium effect sizes: obsessive compulsive personality disorder (high) and histrionic personality (low). Small effect sizes exist for antisocial personality (low), psychopathy (low), narcissistic personality (low), schizoid personality (high) and borderline personality (low). In our view, the context of the assessment can partially explain these results but not entirely. The results do not confirm previous studies and question the high rates of psychiatric prevalence in prison.