The prevalence of dyslexia and AD/HD in a sample of forensic psychiatric rapists.

Research paper by Anna M AM Dåderman, May M Lindgren, Lars L Lidberg

Indexed on: 30 Oct '04Published on: 30 Oct '04Published in: Nordic journal of psychiatry


The prevalence of dyslexia and attention deficit/hyperactivity disorder (AD/HD) (DSM-IV) is markedly increased among those who are sentenced for criminal offences. The aim of the study was to identify developmental disabilities, dyslexia and AD/HD among severely disturbed men in forensic psychiatric care, and to study the co-occurrence of such disabilities, with the objective to discuss the importance of the diagnoses in forensic psychiatry. The participants were 10 males who had committed rape on adult women, and included two murder-rapists, one of which had murdered more than one victim (i.e. a serial murderer). All had been assigned to special long-term forensic psychiatric care, based predominantly on a psychodynamic ground. In order to be identified as having dyslexia, a participant's performance on at least three out of four tests of academic skills had to be markedly below the expected level (more than two stanine steps), given the participant's non-verbal intellectual capacity and considering the length of his education. AD/HD was investigated by studying the participants' forensic psychiatric files and by a clinical interview. Seven of the 10 participants met the DSM-IV criteria for dyslexia, and six of them met the DSM-IV criteria for AD/HD. Four participants had AD/HD and dyslexia, three had AD/HD but no dyslexia, and two had dyslexia but no AD/HD. Only one participant had neither dyslexia nor AD/HD. The participants with dyslexia performed well in tests assessing non-verbal reasoning, visuo-spatial capacity and visual memory. Although the generalization of the results from 10 rapists is severely limited, the results indicate the importance of assessing dyslexia as well as AD/HD in people who are admitted for forensic psychiatric assessment. The lack of correct diagnoses may negatively influence the choice of appropriate forensic psychiatric care. Early assessment of those disorders might have a positive influence on the psychological development and socialization process in people with dyslexia and/or AD/HD.