Background: Life expectancy is on rise and the intriguing question is: When does cognitive decline occur among adults with intellectual disability, compared to adults with typical development? This cross-sectional study examined cognitive performance of crystallised/fluid intelligence, working and long-term memory of adults with intellectual…

Goals: This study examined: (a) crystallized/fluid intelligence trajectories of adolescents and adults with Down syndrome; and (b) the contribution of endogenous (health, activities of daily living--ADL) and exogenous (cognitively stimulating leisure activities) factors on adults' intelligence with age. Method: Four cohorts (N = 80) with Down…

Introduction: Intellectual disability is a key subject in all mental healthcare institutions, including the forensic mental health services. The Screener for Intelligence and Learning Disability (SCIL) is designed to screen for intellectual disability in forensic populations. So far, this assessment method is only validated in "detention fit…

Background: The Learning Disability Screening Questionnaire (LDSQ) has been shown to have high sensitivity and specificity to identify those who are likely to meet intellectual disability diagnostic criteria (McKenzie, et al. [McKenzie K., 2015]). However, there is no independent research to date to support these findings. Materials and Methods:…

Background: A stable assessment of cognition is of paramount importance for forensic psychiatric patients (FPP). The purpose of this study was to compare repeated measures of IQ scores in FPPs with and without intellectual disability. Methods: Repeated measurements of IQ scores in FPPs (n = 176) were collected. Differences between tests were…

Objective: It has been suggested that, as the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) give a scaled score of one even if a client scores a raw score of zero, these assessments may have a hidden floor effect at low IQ levels. The study looked for…

Background: Previous research with earlier versions of the WISC and WAIS has demonstrated that when administered to people who have intellectual disabilities, the WAIS produced higher IQ scores than the WISC. The aim of this study was to examine whether these differences still exist. A comparison of the Wechsler Adult Intelligence Scale-Third…

Background: Whether the Flynn effect (the increase in the populations' IQ over time) affects the IQ scores of people with learning disability or borderline learning disability remains unclear. The issue is important as the Flynn effect should alter the number of people eligible for health service resources. A comparison of the Wechsler Adult…