title: Disease-related and genetic correlates of psychotic symptoms in Parkinson's disease.
abstract: Our aim was to examine disease-related and genetic correlates of the development of psychotic symptoms in a large population of patients with Parkinson's disease. We studied 500 patients with Parkinson's disease from the NeuroGenetics Research Consortium using logistic regression models. Predictors were demographic, clinical (motor/nonmotor features), and genetic, measured as continuous or dichotomous variables. Continuous measures were divided into population-based tertiles. Results are given as odds ratios (95% confidence intervals) for dichotomous variables and by ascending tertile for continuous variables. Psychotic symptoms were associated with increasing age: 4.86 (1.62-14.30) and 6.25 (2.09-18.74) (test for trend: P = 0.01); and duration of disease: 3.81 (1.23-11.76) and 5.33 (1.68-16.89) (test for trend: P = 0.03). For nonmotor features, we demonstrated positive trends with depression: 1.31 (0.47-3.61) and 5.01 (2.04-12.33) (test for trend: P < 0.0001); cognitive dysfunction: 0.69 (0.26-1.84) and 2.51 (1.00-6.29) (test for trend: P = 0.03); and an excess for those with sleep disorders: 2.00 (1.03-3.89) (P = 0.04). Psychotic symptoms were not associated with tremor or postural instability scores, but there was an association with freezing of gait: 3.83 (1.67-8.75) (P < 0.002). Psychotic symptoms were not associated with the presence of any examined polymorphisms in the apolipoprotein, alpha-synuclein, or microtubule associated protein tau genes. This is the largest study to examine correlates of psychotic symptoms in Parkinson's disease. We discovered a novel association with freezing of gait. We demonstrated an association with depression and duration of disease, both of which were inconsistently related in previous studies, and confirmed the association with age, cognitive dysfunction, and sleep disorders.
authors.affiliation: Department of Neurology, Emory University School of Medicine, 1841 Clifton Road NE, Atlanta, GA 30329, USA. sfactor@emory.edu
authors.forename: Stewart A
authors.initials: SA
authors.lastname: Factor
authors.forename: N Kyle
authors.initials: NK
authors.lastname: Steenland
authors.forename: Donald S
authors.initials: DS
authors.lastname: Higgins
authors.forename: Eric S
authors.initials: ES
authors.lastname: Molho
authors.forename: Denise M
authors.initials: DM
authors.lastname: Kay
authors.forename: Jennifer
authors.initials: J
authors.lastname: Montimurro
authors.forename: Ami R
authors.initials: AR
authors.lastname: Rosen
authors.forename: Cyrus P
authors.initials: CP
authors.lastname: Zabetian
authors.forename: Haydeh
authors.initials: H
authors.lastname: Payami
mesh_terms: D000367:Age Factors; D000368:Aged; D001057:Apolipoproteins E / Q000235:genetics*; D003072:Cognition Disorders / Q000209:etiology; D018672:Community Health Planning; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications* / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011618:Psychotic Disorders / Q000209:etiology* / Q000235:genetics; D012307:Risk Factors; D012720:Severity of Illness Index; D051844:alpha-Synuclein / Q000235:genetics*; D016875:tau Proteins / Q000235:genetics*
chemical_list: D001057:Apolipoproteins E; C054369:MAPT protein, human; C497604:SNCA protein, human; D051844:alpha-Synuclein; D016875:tau Proteins