اختلالات فکری و روانی (PCL-R) در یک نمونه روانی پزشکی قانونی مجرمان قتل: برخی از مسائل قابلیت اطمینان

Several studies have shown that psychopathy is overrepresented among homicide offenders. There is a consensus that Hare's Psychopathy Checklist-Revised PCL-R is currently the most valid and useful tool for rating psychopathy (e.g., [Fulero, S. M. (1995). Review of the Hare Psychopathy Checklist-Revised. In J. C. Conoley & J. C. Impara (Eds.), Twelfth Mental Measurements Yearbook (pp. 453–454). Lincoln, NE: Buros Institute]). Usually, when making a rating of psychopathy, both an interview and an examination of the subject's files are used. However, it has been discussed what is really required to be able to rate psychopathy in a reliable manner. The aim of the present study was to retrospectively rate the degree of psychopathy in 35 homicide offenders being subjected to forensic psychiatric assessment. These ratings of psychopathy were carried out using forensic psychiatric files and courts'; verdicts only. Another aim was to examine the reliability of PCL-R in this specific Swedish sample of homicide offenders. There was a good agreement between the two raters with respect to the categorical diagnosis of psychopathy (Cohen's kappa = .81, p < .001), which indicates that retrospective ratings of psychopathy are well suited for research purposes. The prevalence of psychopathy among the homicide offenders was 31.4% (using a cut-off score of 30), which means that the construct of psychopathy may contribute to the understanding of the phenomenon of homicide. In the planning of treatment for homicide offenders, a consideration of possible psychopathy is necessary. As criminal psychopaths are known to relapse into violent criminality, it is very important that they are given efficient treatment, placement and management.

1.1. The concept of psychopathy Psychopathy is a concept with a long and contentious history. Several different definitions of psychopathy have been used throughout history. The first well-founded concept of psychopathy was put forward by the American psychiatrist Hervey Cleckley. His book, The Mask of Sanity ( Cleckley, 1988), had a major impact during the 1940s following the publication of the first edition. Cleckley defined, in the book, psychopathy through a series of case vignettes. Cleckley identified certain characteristics that a person must have in order to be considered psychopathic. However, he was not of the opinion that all of the characteristics must be present in order for a person to be diagnosed as been a psychopath. The characteristics listed by Cleckley included superficial charm, high IQ, lack of remorse or shame, antisocial behaviour, poor judgement, a failure to learn from experience, pathological egocentricity, an inability to maintain a normal loving relationship, a lack of strong emotional relationships, and a shallow and poorly arranged sex life. The Mask of Sanity has formed the basis of extensive research in the field for the last 25 years. The research that has been conducted during these years has primarily aimed at describing the characteristics of a psychopath, but methods have also been developed to facilitate the identification of psychopaths ( Hare, 1997). A contemporary researcher in the field who has received considerable attention is the Canadian psychologist Robert Hare. He states that a psychopath is a person without a conscience, whose life centres on his/her own satisfaction, often at the expense of others, and a person who lacks empathy and the ability to establish warm, loving relationships. Hare used case studies to develop a method for diagnosing psychopaths, using a checklist of characteristics distinctive for psychopathy. The checklist consists of 20 items and is known as The Psychopathy Checklist Revised (PCL-R; Hare, 1991). The items from the PCL-R may be subdivided into two factors; Factor 1 — interpersonal traits that are central to psychopathy, such as glibness/superficial charm and manipulativeness; and Factor 2 — antisocial behaviour such as early behavioural problems and impulsivity. Three items from the checklist (promiscuous sexual behaviour, many short-term marital relationships and criminal versatility) do not correlate with either of the two factors. Each item is rated on a three-point scale; where 0 points means that the characteristics and behaviour of the person do not agree with the item to any degree, 1 point means that the item applies to a given person to a certain extent, and 2 points mean that the item applies closely to a given person. A total score of 30 or more is indicative of psychopathy. In order to be able to determine the total score of psychopathy as correct as possible, a manual is used that describes in detail what is to be considered for each item. At least 15 of the 20 items must be rated for a PCL-R score to be valid. Unrated items are replaced by a mean value based on the total expected result as described in Hare's manual (Hare, 1991). 1.2. The degree of psychopathy in homicide offenders Firestone, Bradford, Greenberg, and Larose (1998) investigated the degree of psychopathy in offenders convicted of incest and in offenders convicted of sex-related murder. The authors found that the homicide offenders scored higher on PCL-R than those convicted of incest with respect both to Factor 1 (interpersonal traits) and Factor 2 (antisocial behaviour) and also with respect to the total score. A thesis by Thomas (2001) likewise showed that offenders who murdered their victims were rated significantly higher on PCL-R than those who did not. Firestone, Bradford, Greenberg, Larose, and Curry (1998) showed that offenders who murdered children scored significantly higher on PCL-R than those who molested children without murdering them. Myers and Blashfield (1997) studied 14 young offenders guilty of sex-related murder. They used a cut-off level at a score of 27 on PCL-R to identify psychopathy, and identified 36% of the young offenders as psychopaths. Woodworth and Porter (2002) studied 125 homicide offenders. They found 34 (27%) psychopaths in this group (using a cut-off score of 30 on PCL-R as a definition of psychopathy). 1.3. Diagnosing psychopathy with or without an interview It is normal when rating psychopathy to use both an interview and an examination of the subject's files (Hare, 1991). The interview should cover such matters as family life, economic situation, career, and criminal background. Many believe that PCL-R is currently the most valid and useful tool for rating psychopathy (e.g., Fulero, 1995). However, it has been discussed what is really required in order to be able to rate psychopathy in a reliable manner. The requirement for an interview has been investigated in a number of studies (Grann et al., 1998, Serin, 1993 and Wong, 1988). The opportunity to rate psychopathy without needing to use an interview would be advantageous, as this would reduce the time needed for the rating, and also make it possible to carry out various retrospective studies. It would also be possible to rate psychopathy long after the original forensic psychiatric assessment, (FPA) even if an interview as specified in the manual for PCL-R was not carried out at that time (Grann et al., 1998). Wong (1988) showed that it was possible to rate psychopathy, using PCL-R, reliably without an interview. However, Serin (1993) found a poor correlation between ratings based solely on files and ratings based on files plus interviews. There was also poor agreement with respect to the categorical diagnosis of psychopathy (yes or no) between groups when comparing these two methods of rating. More than 40% of the subjects received different diagnoses under the two different methods. Nevertheless the results suggested that between independent ratings of psychopathy based on files alone the interrater reliability was high, and likewise there was high interrater reliability between independent ratings based on both files and interviews. Grann et al. (1998) also investigated the reliability of retrospective file rating, without interview, according to PCL-R. The ratings of Stålenheim (one of the authors in the study of Grann et al.), who is a forensic psychiatrist and trained in the use of PCL-R, carried out with the aid of both files and thorough interviews, were compared with those of three other raters, who rated the same patients completely independently using forensic psychiatric files and information from police records. These three raters had only received 2 days of training (a seminar on the clinical use of PCL-R). There was a good agreement between these two types of rating. However, the raters not using an interview tended to assign relatively higher PCL-R scores to patients with low scores, and relatively lower scores to patients with high scores. The raters agreed somewhat better with respect to Factor 2 than they did with respect to Factor 1. As mentioned, previous research (Grann et al., 1998, Serin, 1993 and Wong, 1988) shows that retrospective ratings of psychopathy using PCL-R tend to underestimate the degree of psychopathy in people with high scores. This has led researchers to discuss the possibility of using a cut-off score (the lowest score for a diagnosis of psychopathy) lower than 30 in retrospective studies. For example, Grann et al. (1998) found an optimal cut-off score for psychopathy at 26, whereas Dåderman and Kristiansson (2003) suggested an optimal cut-off score at 27. A pilot study (Laurell, 2002) to the present study compared retrospective ratings by the first author with those of another student, and with previous clinical ratings carried out by personnel active within forensic psychiatry. These people had received special training in rating psychopathy according to PCL-R and were experienced in this rating. The clinical ratings agreed well with the retrospective ratings; the intra-class correlation coefficient (ICC) showed that interrater reliability was high (ICC(2,1) = .97, F(5,6) = 66.72, p < .0001). 1.4. Aims The main aim was to perform retrospective ratings of the degree of psychopathy of 35 male homicide offenders subjected to an FPA. These ratings were carried out using forensic psychiatric files and courts' verdicts. Another aim was to compare the ratings of psychopathy carried out by two independent raters with respect to the same group of 35 participants in order to study the reliability of the psychopathy checklist, PCL-R. Previous research led us to expect a high prevalence of psychopathy in homicide offenders, and a good agreement between the ratings of the two raters with respect to psychopathy.