summary A 66-year-old patient had suffered from late-onset schizophrenia from the age of 44. Her family history included reports of brain haemorrhages, possibly resulting from hereditary amyloidal angiopathy of the Dutch type (Katwijk disease). She was very afraid for having this disease. The progression of the psychiatric symptoms and the age at which they began, led us to suspect an organic process. Differential diagnoses that were discussed included cerebral amyloidal angiopathy, frontal lobe dementia and Huntington's disease.