Incidence and relationship between behavioural and psychological symptoms in Alzheimer's disease

OBJECTIVES: To evaluate the frequency and type of psychological and behavioural symptoms in Alzheimer's disease (AD) patients in Poland, in various stages of the disease. METHOD: One hundred and sixty-nine patients with a diagnosis of probable AD in Global Deterioration (GDS) stages 3, 4, 5, 6 and 7 of dementia were examined in a search for behavioural and psychological symptoms. RESULTS: Behavioural and psychotic symptoms were most often found in GDS stages 5 and 6 of AD, except for depressive disorder, which was observed most frequently in GDS stage 4 and whose frequently decreased towards the terminal stages of dementia. From an analysis of the relationship between behavioural symptoms in the Polish AD patients, the following syndromes may be discriminated: psychotic syndrome (delusions and hallucinations), delusions with aggressive behaviour and hallucinations and anxiety. With more severe dementia, the syndromes, which could be the result of delirium, became more common. CONCLUSIONS: Diagnosis of delirium should be considered in moderately severe and severe dementia whenever a sudden change in patients' behaviour occurs.