Four Components Describe Behavioral Symptoms in 1,120 Individuals with Late-Onset Alzheimer's Disease

Authors

  • Paul Hollingworth PhD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Marian L. Hamshere PhD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Valentina Moskvina PhD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Kimberley Dowzell BSc,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Pamela J. Moore MA,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Catherine Foy PhD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Nicola Archer BA,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Aoibhinn Lynch MRCPsych,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Simon Lovestone PhD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Carol Brayne MD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • David C. Rubinsztein PhD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Brian Lawlor MD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Mike Gill MD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Michael J. Owen PhD,

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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  • Julie Williams PhD

    1. From the *Department of Psychological MedicineBiostatistics and Bioinformatics Unit, Cardiff University School of Medicine, Heath Park, Cardiff, United KingdomInstitute of Psychiatry, Kings College, De Crespigny Park, Denmark Hill, London, United Kingdom§Mercer's Institute for Research on Aging, St. James's Hospital and Trinity College, Dublin, IrelandInstitute of Public Health#Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
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Address correspondence to Professor Julie Williams, Department of Psychological Medicine, Cardiff University School of Medicine, Heath Park, Cardiff, CF14 4XN, United Kingdom. E-mail: williamsj@cardiff.ac.uk

Abstract

OBJECTIVES: To investigate behavioral components of Alzheimer's disease (AD) and to analyze behavioral components in relation to disease severity, apolipoprotein E genotype (APOE), sex, years of education, age at onset, and cognitive impairment.

DESIGN: Cross-sectional study.

SETTING: Data were collected from community-dwelling individuals and those residing in nursing homes.

PARTICIPANTS: A total of 1,120 individuals meeting National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria for late-onset probable AD.

MEASUREMENTS: Behavioral symptoms were assessed using the Neuropsychiatric Inventory. First-order polychoric correlations, controlling for disease severity, between the 12 symptom domain scores were estimated, and the resulting matrix underwent principal components analysis.

RESULTS: Four interpretable components were identified: behavioral dyscontrol (euphoria, disinhibition, aberrant motor behavior, and sleep and appetite disturbances), psychosis (delusions and hallucinations), mood (depression, anxiety, and apathy), and agitation (aggression and irritability). Scores on the four components were associated with severity of cognitive impairment. Higher behavioral dysfunction, agitation, and mood component scores were associated with lower age at onset. Behavioral dysfunction and mood component scores were associated with sex. None of the components were associated with age at assessment, years of education, or number of APOE ɛ4 alleles.

CONCLUSION: Four behavioral components were identified that were comparable with those observed previously. Future analysis of these components will strengthen understanding of the underlying pathology of behavioral symptoms and AD.

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