Objectives. Inconclusive results have been obtained so far in the research into the apolipoprotein E (APOE) genotype association with either behavioral and psychological symptoms of dementia (BPSD) or psychotic symptoms in Alzheimer 's disease (AD). However, many studies suggest a possible relationship between psychotic symptoms, especially delusions, and the presence of at least one e4 allele. The aim of the study was to assess the prevalence and severity of BPSD in relation to the APOE genotype.
Method. A cohort of 54 highly selected AD patients was included in the study The patients were evaluated using the Clinical Dementia Rating scale (CDR; for dementia severity), two psychometric scales (ADAS-cog and MMSE; for the cognitive dysfunction profile), and the Neuropsychiatric Inventory (NPI; for the presence and severity of BPSD). APOE genotyping was performed using the standardized protocol.
Results. APOE e4 allele carriers were at a substantially higher risk of exhibitng psychotic symptoms (particularly delusions, but not hallucinations analyzed separately), as well as agitation/aggression. This association was more pronounced in moderately than in mildly demented subjects. No association between the APOE genotype and other behavioral or psychological symptoms was noted.
Conclusions. The risk of developing delusions or hallucinations might be differentially modulated by the presence of APOE e4 allele. Further research is needed to evaluate the significance of other genetic polymorphisms for the risk of BPSD.