Older adults are hardly ever diagnosed as having autism spectrum disorders (asd). Only a few case-studies have been published and there has been no quantitative research into these developmental disorders in the 60-plus age group. Diagnosis is made more complicated because it is difficult to obtain a developmental history in older adults. It is possible that behavioural aspects are different in later life because of the biopsychosocial factors that are linked to ageing. Further scientific research is needed into differential diagnoses in older adults.