There was a significant association between the number of APOE epsilon4 alleles and prevalence and severity of neuropsychiatric and behavioral symptoms that was mainly attributable to delusions and agitation/aggression, which were more common and severer among homozygous APOE epsilon4 carriers.
Multiple logistic regression models were used to calculate the association between the ApoE epsilon4 allele and the presence of psychotic symptoms (delusions or hallucinations).
In this study, which considers the entire range of behavioural expressions in LOAD patients at the early stage of the illness, the relationship between behaviour and ApoE epsilon4 allele is confirmed for delusions only.
ApoE epsilon4 noncarriers showed better improvement in mean total BEHAVE-AD score and mean psychosis (delusions and hallucinations) subscale score than ApoE epsilon4 carriers.
This study demonstrated no relationship between presence of the APOE epsilon4 allele and any of the behavioural symptoms assessed, including delusions, hallucinations, depression, activity disturbances, aggressiveness and anxiety.
We investigated the association of 5-HTTLPR with delusions in a total of 257 consecutive patients clinically diagnosed as AD according to the National Institute on Aging-Alzheimer's Association criteria.
We tested four genes [phenylalanine hydroxylase (PAH), the serotonin transporter (SLC6A4), monoamine oxidase B (MAOB), and the gamma-aminobutyric acid A receptor beta-3 subunit (GABRB3)] for their impact on five schizophrenia symptom factors: delusions, hallucinations, mania, depression, and negative symptoms.