Faculty for People with Intellectual Disabilities Guidance on the Assessment and Diagnosis of Intellectual Disabilities in Adulthood A document compiled by a Working Group of the British Psychological Society’s Division of Clinical Psychology, Faculty for People with Intellectual Disabilities Membership of the Working Group This document has been prepared by the Faculty for People with Intellectual Disabilities of the Division of Clinical Psychology, the British Psychological Society. Membership of the Working Group was as follows: Theresa Joyce (Chair); Ivan Bankhead; Terry Davidson; Susan King; Heather Liddiard; Paul Willner. Acknowledgements Grateful thanks are extended to all those who commented on earlier drafts of the document, and all those who attended the workshops as part of the consultation process. If you have problems reading this document because of a visual impairment and would like it in a different format, please contact us with your specific requirements. Tel: 0116 252 9523; Email: [email protected] For all other enquires please contact the Society on: Tel: 0116 254 9568; Email: [email protected] Printed and published by the British Psychological Society. © The British Psychological Society 2015 The British Psychological Society St Andrews House, 48 Princess Road East, Leicester LE1 7DR, UK. Tel: 0116 254 9568 Facsimile: 0116 247 0787 Email: [email protected] Website: www.bps.org.uk Incorporated by Royal Charter Registered Charity No 229642 Contents Executive Summary ................................................................................................................ 2 Introduction ............................................................................................................................ 3 Section 1: Contexts ................................................................................................................ 6 1.1 England and Wales ................................................................................................... 6 1.2 Scotland ..................................................................................................................... 9 1.3 Northern Ireland ...................................................................................................... 10 Section 2: Defining intellectual disability ............................................................................. 12 2.1 Significant impairment of intellectual functioning ................................................ 12 2.2 Significant impairment of adaptive behaviour ....................................................... 13 2.3 Age of onset prior to adulthood .............................................................................. 14 2.4 Levels of intellectual disability ................................................................................. 14 Section 3: Assessing intellectual disability ............................................................................ 16 3.1 Gathering preliminary information ........................................................................ 16 3.2 Selecting appropriate assessment measures ........................................................... 16 Measures for the assessment of intellectual functioning ....................................... 16 Measures for the assessment of adaptive behaviour ............................................... 17 3.3 Conducting an assessment ....................................................................................... 19 Factors in the assessment of intellectual functioning ............................................ 19 Factors in the assessment of adaptive behaviour .................................................... 21 Section 4: Interpreting the results of an assessment ............................................................ 22 4.1 Clinical judgement ................................................................................................... 22 4.2 Significant impairment of intellectual functioning ................................................ 23 4.3 Significant impairment of adaptive behaviour ....................................................... 24 4.4 Age of onset prior to adulthood .............................................................................. 25 4.5 Severe intellectual disability ..................................................................................... 26 4.6 The need for concurrence of the three criteria ..................................................... 26 Section 5: Reporting on assessments .................................................................................... 27 5.1 Identifying information ............................................................................................ 27 5.2 Reason for referral .................................................................................................... 27 5.3 Background information ......................................................................................... 28 5.4 Appearance and behavioural observations ............................................................. 28 5.5 Tests administered .................................................................................................... 28 5.6 Test results and interpretation ................................................................................. 28 5.7 Summary, diagnostic impression and recommendations ...................................... 29 Appendix 1: Intellectual disability and comparable terminology over the years ............... 31 Appendix 2: The consultation process .................................................................................. 32 References .............................................................................................................................. 33 Guidance on the Assessment and Diagnosis of Intellectual Disabilities in Adulthood 1 Executive Summary This document has been produced as guidance for clinical psychologists who are frequently asked to assess whether or not an individual has an intellectual disability. It will also be of use to commissioners, colleagues in intellectual disability services and families and individuals who are seeking clarification on this issue. The aim is to outline good practice in this area. It also considers the different contexts in which assessment of intellectual disability may be relevant, including mental health and mental capacity legislation, court proceedings, service entitlement and the family courts. Intellectual disability is defined as significant impairment in intellectual functioning and significant impairment in adaptive behaviour (social functioning), with each of these impairments beginning prior to adulthood. In practice, a diagnosis of intellectual disability is sometimes made without reference to all three criteria and with debate over the meaning of scores on an assessment of intellectual functioning (usually known as an IQ test). This has resulted in confusion for families, service users and care providers and consequent difficulties in ensuring that individuals receive an appropriate service. This document seeks to clarify the components of an assessment, considers the meaning of the ‘scores’ that are obtained and outlines the means by which psychologists reach their opinion in relation to whether or not an individual has an intellectual disability. It provides guidance on technical issues, and notes the difficulties associated with assessing intellectual functioning for people who have an intellectual disability. It also notes the relevance of psychologists using their clinical judgement in interpreting complex information. The document recommends specific measures that should be used, and provides guidance on how findings should be presented. It also notes the importance of ensuring that assessment is undertaken by an appropriately qualified psychologist. A further recommendation is that a judgement as to whether or not an individual has an intellectual disability should only be made when all three components of the assessment are carried out by an appropriately qualified professional, who is able to justify their opinion in accordance with this guidance. This would reduce confusion for individuals, families and services. 2 Guidance on the Assessment and Diagnosis of Intellectual Disabilities in Adulthood Introduction This document has been produced by the Faculty for People with Intellectual Disabilities of the Division of Clinical Psychology, the British Psychological Society (the Society), to provide updated guidance to psychologists registered with the Health and Care Professions Council (HCPC) who may be required to assess the presence of intellectual disability, or the extent of intellectual disability, in adults. Intellectual disability is the term used internationally to describe what was previously known as learning disability. The term intellectual disability will be used throughout this document. 1 National and international definitions of intellectual disability generally share three key criteria. These are: l a significant impairment of intellectual functioning; l a significant impairment of adaptive behaviour (social functioning); with l both impairments arising before adulthood. These criteria are embodied in mental health and mental capacity legislation in the United Kingdom. They are also evident in the major diagnostic classification systems of the American Association on Intellectual and Developmental Disabilities (AAIDD) , the American Psychiatric Association