TY - JOUR AB - Purpose Assessment of psychiatric disorders in people with autism spectrum disorder (ASD) and intellectual disabilities (ID) is challenging. The purpose of this paper is to explore the diagnostic decision making and strategies employed in the assessment of a young man with ASD and ID who eventually got the additional diagnosis of schizophrenia.Design/methodology/approach To describe and explore a process not easily converted into quantitative measures, it was chosen to perform a case study of a single case.Findings The combined knowledge of ASD, ID and psychiatric disorder was important in the current assessment. General assessment tools were of some value, but their results had to be interpreted with care. The same was true of a more ASD/ID-specific tool. Using multiple informers may strengthen data from such tools in this population, but does not make it interchangeable with self-report. The case presented demonstrates the possibility of negative symptoms and functional decline overshadowing positive psychotic symptoms in people with ASD/ID, as well as the expression of ASD changing with a functional decline.Originality/value The present study adds to the few previous reports on identification of psychosis in this population, and in addition, may assist clinicians in making more accurate psychiatric assessments of people with ASD/ID. VL - 11 IS - 1 SN - 2044-1282 DO - 10.1108/AMHID-11-2016-0036 UR - https://doi.org/10.1108/AMHID-11-2016-0036 AU - Kildahl Arvid Nikolai AU - Bakken Trine Lise AU - Holm Olaf Kristian AU - Helverschou Sissel Berge PY - 2017 Y1 - 2017/01/01 TI - Assessment of psychosis in ASD/ID: a case study T2 - Advances in Mental Health and Intellectual Disabilities PB - Emerald Publishing Limited SP - 17 EP - 23 Y2 - 2024/04/25 ER -