Diagnosing a disorder of sexual preference may have far-reaching consequences. Apart from informing treatment options, such a diagnosis will likely have implications for risk assessment. Consequently, offenders with corresponding diagnoses may be incarcerated or hospitalized for considerable periods of time, placed under strict monitoring regulations, or even be detained indeterminately. Therefore, diagnoses concerning disorders of sexual preference should be made with the utmost diligence. As there is commonly no gold standard of assessment in forensic psychology and psychiatry, agreement among observers is generally imperfect. Another source of error is the prevalence of the disorder. The prevalence, however, can only be estimated given the absence of a gold standard. The implications of these two sources of uncertainty--imperfect inter-rater agreement and sampling variation--will be highlighted with respect to the diagnosis of pedophilia. How likely is a diagnosis of pedophilia actually true, given reliability, its sampling variation, and the prevalence range? The results will be discussed in view of recent findings on the field reliability of assessment procedures in forensic psychology and psychiatry.
Andreas Mokros studied Psychology at the Universities of Bochum (Dipl.-Psych.), Liverpool (M.Sc. in Investigative Psychology), and Wuppertal (Ph.D.). He is a research psychologist in the Department for Forensic Psychiatry at the University Hospital of Psychiatry Zurich, Switzerland. He is also an adjunct senior lecturer (Privatdozent) in the Department of Psychology at the University of Regensburg, Germany. His research interests include indirect cognitive assessment methods, psychopathy, and quantitative methods.