Steroid Hormones and Severity of Psychopathy in Forensic Patients

The steroid hormones testosterone and cortisol, high and low levels, respectively, are suggested to drive status-relevant behavior like aggression and dominance. Therefore, these steroids have also been linked to psychopathy. It is however unclear to what extend basal steroid levels, or their (in)flexibility over time, can account for severity of psychopathy as most studies either compare psychopaths to healthy individuals or focus on psychopathic traits within a healthy population. We investigated whether steroid levels, their fluctuations over time and their ratio (i.e., the testosterone-cortisol ratio) are associated with the severity of psychopathy as assessed with the 4 facet-model of the Psychopathy Checklist Revised (PCL-R). Steroid saliva levels were assayed in 20 male psychopathic patients (PCL-R score >= 26) before and after patients participated in a within-subjects oxytocin administration protocol. Steroid levels, particularly cortisol, decreased across the test-protocol, which was not affected by oxytocin administration. Interestingly, steroid levels remained stable in psychopaths with severely distorted narcissistic and manipulative behavioral interpersonal tendencies (PCL-R facet 1), and baseline testosterone levels were higher in psychopaths with severe antisocial tendencies (PCL-R facet 4). Together these results confirm that basal steroid levels, as well as their fluctuation over time, are associated with psychopathic severity. Future endocrine research in psychopathy should take account of its behavioral diversity and focus on a combination of basal steroid levels and their change over time.