People with a learning disability are just as likely as people in the general population to be at risk of cerebrovascular disease, due to the presence of undetected/undertreated vascular risk factors. When people with a learning disability are presenting with additional cognitive impairment, it is important to consider a range of conditions that may account for this. Stroke is a major cause of cognitive impairment in older people, affecting at least one-third of stroke survivors (Leeds et al. 2001). However, post-stroke psychosis is rare following stroke, and, as can be seen from the case of "May", individuals can make a good recovery with appropriate assessment and intervention. It is important that a diagnosis of dementia is given only after all other potentially treatable conditions have been excluded, and there is a stepwise global deterioration without any other explanation.