Psychotic symptoms in Alzheimer's disease and 5-HTTLPR polymorphism of the serotonin transporter gene: evidence for an association.
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 epsilon4 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.
Quaranta
Davide
D
Institute of Neurology, Catholic University of Sacred Heart, Rome, Italy.
Bizzarro
Alessandra
A
Marra
Camillo
C
Vita
Maria Gabriella
MG
Seripa
Davide
D
Pilotto
Alberto
A
Sebastiani
Valeria
V
Mecocci
Patrizia
P
Masullo
Carlo
C
D000203:Activities of Daily Living; D000368:Aged; D000483:Alleles; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology*; D001057:Apolipoproteins E / Q000235:genetics; D003071:Cognition / Q000502:physiology; D004493:Education; D005260:Female; D005838:Genotype; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D017533:Marital Status; D009483:Neuropsychological Tests; D009790:Occupations; D011110:Polymorphism, Genetic / Q000235:genetics; D011618:Psychotic Disorders / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
D001057:Apolipoproteins E; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins