There is general consensus in clinical and research literature that the core feature of psychopathy consists of an affective deficit. However, previous studies tend to find weak and inconsistent associations between psy- chopathy and measures of internalizing psychopathology. In this study we test whether the predominant practice of using questionnaires to assess internalizing psychopathology has influenced the results of previ- ous research. We argue that questionnaires measure general distress rather than specific symptoms of inter- nalizing psychopathology, and that the validity of questionnaires might be impaired by psychopathic traits, such as impression management and lack of affective experience. Combining a questionnaire (Depression Anxiety Stress Scales-21; DASS-21) and a semi-structured interview (Structured Clinical Interview for DSM-IV-R Axis 1 Disorders; SCID-I) for internalizing psychopathology, we test the differential association of both measures with the Psychopathy Checklist—Revised (PCL-R) in a sample of 89 male detainees. In ac- cordance with our prediction, we found moderate negative associations between the Interpersonal and Affec- tive facets of the PCL-R and SCID-I, but no significant associations with the DASS-21. We found no evidence that psychopathic traits decrease the validity of the responses on a questionnaire. We conclude that the in- terpersonal and affective features of psychopathy are negatively related to specific symptoms of internalizing psychopathology, but not with general distress.
Willemsen, J., & Verhaeghe, P. (2012). Psychopathy and internalizing psychopathology. International Journal of Law and Psychiatry, 35(4), 269-275. https://doi.org/10.1016/j.ijlp.2012.04.004 (Original work published 2012)