Forskningsartikler

Introduction: Individuals with Alzheimer’s disease (AD) commonly experience neuropsychiatric symptoms of psychosis (AD+P) and/or affective disturbance (depression, anxiety, and/or irritability, AD+A). This study’s goal was to identify the genetic architecture of AD+P and AD+A, as well as their genetically correlated phenotypes.
Methods:
Genome-wide associationmeta-analysis of 9988 AD participants from six source studies with participants characterized for AD+PAD+A, and a joint phenotype (AD+A+P).
Results:
AD+P and AD+A were genetically correlated. However, AD+P and AD+A diverged in their genetic correlations with psychiatric phenotypes in individuals without AD. AD+P was negatively genetically correlated with bipolar disorder and positively with depressive symptoms.AD+Awas positively correlatedwith anxiety disorder and more strongly correlated than AD+P with depressive symptoms. AD+P and AD+A+P had significant estimated heritability, whereasAD+A did not. Examination of the loci most strongly associated with the three phenotypes revealed overlapping and unique associations.
Discussion:
AD+P, AD+A, and AD+A+P have both shared and divergent genetic associations pointing to the importance of incorporating genetic insights into future treatment development.

Inga Margret Antonsdottir, Byron Creese, Lambertus Klei, Mary Ann A. DeMichele-Sweet, Elise A. Weamer, Pablo Garcia-Gonzalez, Marta Marquie, Mercè Boada, Emilio Alarcón-Martín,  Sergi Valero, NIA-LOAD Family Based Study Consortium, Alzheimer’s Disease Genetics Consortium (ADGC), AddNeuroMed Consortium, Yushi Liu, Basavaraj Hooli, Dag Aarsland, Geir Selbaek, Sverre Bergh, Arvid Rongve, Ingvild Saltvedt, Håvard K. Skjellegrind, Bo Engdahl, Ole A. Andreassen, Barbara Borroni, Patrizia Mecocci, Yehani Wedatilake, Richard Mayeux, Tatiana Foroud, Agustín Ruiz, Oscar L. Lopez, M. Ilyas Kamboh, Clive Ballard, Bernie Devlin, Constantine Lyketsos & Robert A. Sweet

Background: A timely diagnosis of dementia can be beneficial for providing good support, treatment, and care, but the diagnostic rate remains unknown and is probably low.

Objective: To determine the dementia diagnostic rate and to describe factors associated with diagnosed dementia.

Methods: This registry linkage study linked information on research-based study diagnoses of all-cause dementia and subtypes of dementias, Alzheimer’s disease, and related dementias, in 1,525 participants from a cross-sectional population-based study (HUNT4 70+) to dementia registry diagnoses in both primary-care and hospital registries. Factors associated with dementia were analyzed with multiple logistic regression.

Results: Among those with research-based dementia study diagnoses in HUNT4 70+, 35.6% had a dementia registry diagnosis in the health registries. The diagnostic rate in registry diagnoses was 19.8% among home-dwellers and 66.0% among nursing home residents. Of those with a study diagnosis of Alzheimer’s disease, 35.8% (95% confidence interval (CI) 32.6-39.0) had a registry diagnosis; for those with a study diagnosis of vascular dementia, the rate was 25.8% (95% CI 19.2-33.3) and for Lewy body dementias and frontotemporal dementia, the diagnosis rate was 63.0% (95% CI 48.7-75.7) and 60.0% (95% CI 43.3-75.1), respectively. Factors associated with having a registry diagnosis included dementia in the family, not being in the youngest or oldest age group, higher education, more severe cognitive decline, and greater need for help with activities of daily living.

Conclusions: Undiagnosed dementia is common, as only one-third of those with dementia are diagnosed. Diagnoses appear to be made at a late stage of dementia.

Linda Gjøra, Bjørn Heine Strand, Sverre Bergh, Ingunn Bosnes, Aud Johannessen, Gill Livingston, Håvard Kjesbu Skjellegrind & Geir Selbæk