The CAMDEX-DS-II is a standardised structured schedule comprising the assessments necessary for facilitating the diagnosis of dementia in people with Down’s syndrome (a group known to be at particular risk of dementia), as well as others with intellectual disabilities. In order to differentiate decline due to dementia or other mental disorders from pre-existing impairment, particular emphasis has been placed on establishing change from the individual’s best level of functioning. Updated from the original CAMDEX-DS-II, the assessments comprise a structured informant interview to facilitate the systematic collection of information about presenting symptoms and clinical history in order to arrive at a differential diagnosis, and a direct assessment of the patient/participant covering cognitive assessment (CAMCOG-DS-II, providing a reliable way to identify dementia (and to differentiate it from other common disorders). The pack comprises a guidance manual, pictorial booklet, informant interview and CAMCOG-DS neuropsychological test battery. It may be used in community settings by mental health professionals as part of the diagnostic process, or to formalise diagnosis in the context of research.