Objective: To determine the attitudes of patients with mild dementia and their carers towards the disclosure of diagnoses of cancer and dementia and whether there are differences between these groups. To determine whether any major adverse events occurred following disclosure of diagnosis of dementia.Design: A prospective study followed by a retrospective case-note study after 1 year.Participants and Setting: Fifty patients with mild dementia and their carers were recruited from a memory clinic in Nottingham, UK, and an old-age psychiatrist, using a semistructured questionnaire, separately interviewed them.Measures: Questions related to whether patients and their carers wished to be told diagnoses of cancer and dementia; the reasons for this; whether they would want treatment and make use of predictive testing if available were included. At 1-year follow-up whether antidepressants had been prescribed and whether any catastrophic reaction had occurred following disclosure of diagnosis.Results: An overwhelming majority of patients with mild dementia wished to be informed of their diagnosis (92%); even more (98%) of the same patient sample reported wanting disclosure of a hypothetical diagnosis of cancer. A higher proportion (98%) of carers would wish to be told if they were to develop either dementia or cancer. All patients and carers would like access to treatment for dementia. A total of 88% of patients and 86% of carers would make use of a predictive test of Alzheimer's disease. Before receiving a diagnosis of mild dementia, only 28% of patients had insight that they may have dementia. Only a quarter (26%) of carers did not want the doctor to disclose the diagnosis of dementia to the patient. After 1 year, 6% of the original sample had developed a depressive illness requiring antidepressant treatment and no major incidents had occurred following disclosure of diagnosis.Conclusions: There has been a growing debate on whether patients with dementia should be informed of their diagnosis. Until recently, little was known about the views of patients themselves. This study shows that the vast majority of patients with mild dementia wish to be fully informed. Despite increasing awareness, a quarter of carers still do not wish their relative to be informed, though wish to be informed if they themselves were to develop the illness. This is significantly lower, however, than previously reported, suggesting a shift in attitudes. This study adds support to the weight of evidence that disclosure of a diagnosis of dementia does not cause depression or any irreversible harm to the patient. [ABSTRACT FROM AUTHOR]