Affiliations: [a] Institute of Neurology, Catholic University of Sacred Heart, Rome, Italy | [b] Laboratory of Geriatrics & Gerontology, Department of Research, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo (FG), Italy | [c] Geriatric Unit, Department of Medical Sciences, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo (FG), Italy | [d] Institute of Gerontology and Geriatrics, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy
Correspondence:
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Corresponding author: Carlo Masullo, MD, Institute of Neurology, Catholic University of Sacred Heart, Policlinico Universitario ‘A. Gemelli’, Largo A. Gemelli 8, 00168 Roma, Italy. Tel.: +39 6 3015 4435; Fax: +39 6 3550 1909; E-mail: [email protected].
Abstract: The occurrence of psychotic symptoms is common in Alzheimer's disease (AD), configuring a possibly distinguished clinical entity defined “Psychosis in Alzheimer's Disease” (AD-P). In order to investigate demographic clinical and biological variables potentially associated to the occurrence of AD-P, 148 AD patients were selected. Mini-Mental State Examination (MMSE), Activities of Daily Living (ADL), and Instrumental Activities of Daily Living (IADL) scores, socio-economic status and 5-HTTLPR and APOE gene polymorphisms were determined for each subject. AD-P patients were significantly more frequent carriers of the long (L) allele of 5-HTTLPR. The percentage of AD-P increased with the number of copies of the L-allele: 13% among S homozygote; 36% among heterozygotes; 51% among L-homozygotes. No difference resulted between AD-P and non-psychotic AD (AD-NP) in the distribution of the ε4 allele of APOE. The risk of AD-P was increased in L/L homozygous (OR=7.25, p=0.003) and, to a lesser extent, in heterozygous (OR=3.91; p=0.018). Backward logistic regression analysis showed that the risk for AD-P was increased in older subjects (OR=1.07; p=0.018) while an increase of MMSE score was protective (OR=0.90; p=0.004). The occurrence of AD-P resulted significantly related to age at examination, cognitive status, and to the presence of the 5-HTTLPR L-allele.
