The PAS‐ADD assessments (Psychiatric Assessment Schedules for Adults with Developmental Disabilities) have their origins in work that was being conducted over 20 years ago on the health status of older people with intellectual disability. Since that time, the assessments have undergone continuous development and refinement, and now encompass children as well as adults. This paper seeks to discuss some of these fundamental issues and how the PAS‐ADD instruments have attempted to meet these challenges.
The paper includes discussion of theoretical and practical issues that have shaped the development of the assessments.
The fundamental aim of the modern PAS‐ADD system is to improve case detection and assessment by supporting and enhancing the skills of clinical staff, rather than attempting to replace the need for those skills. The assessor makes the final judgement about diagnosis. The PAS‐ADD assessments are based on existing psychiatric classification rules for the general population and are conceptually different from instruments derived from psychometric principles. These factors have major implications, both for instrument design and for the evaluation of effectiveness.
The PAS‐ADD assessments have become widely used in the field of intellectual disability mental health. The theoretical issues discussed here are a central part of the ongoing effort to understand and improve the mental health of people with intellectual disabilities.
