Browsing by Author "Tommet, Douglas"

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    Linking Self-Perceived Cognitive Functioning Questionnaires Using Item Response Theory: The Subjective Cognitive Decline Initiative
    (American Psychological Association, 2023) Rabin, Laura A.; Sikkes, Sietske A. M.; Tommet, Douglas; Jones, Richard N.; Crane, Paul K.; Elbulok-Charcape, Milushka M.; Dubbelman, Mark A.; Koscik, Rebecca; Amariglio, Rebecca E.; Buckley, Rachel F.; Boada, Mercè; Chételat, Gaël; Dubois, Bruno; Ellis, Kathryn A.; Gifford, Katherine A.; Jefferson, Angela L.; Jessen, Frank; Johnson, Sterling; Katz, Mindy J.; Lipton, Richard B.; Luck, Tobias; Margioti, Eleni; Maruff, Paul; Molinuevo, Jose Luis; Perrotin, Audrey; Petersen, Ronald C.; Rami, Lorena; Reisberg, Barry; Rentz, Dorene M.; Riedel-Heller, Steffi G.; Risacher, Shannon L.; Rodriguez-Gomez, Octavio; Sachdev, Perminder S.; Saykin, Andrew J.; Scarmeas, Nikolaos; Smart, Colette; Snitz, Beth E.; Sperling, Reisa A.; Taler, Vanessa; van der Flier, Wiesje M.; van Harten, Argonde C.; Wagner, Michael; Wolfsgruber, Steffen; Alzheimer’s Disease Neuroimaging Initiative; Canadian Longitudinal Study on Aging; Health and Aging Brain Study; Health Disparities (HABS-HD) Study Team; Radiology and Imaging Sciences, School of Medicine
    Objective: Self-perceived cognitive functioning, considered highly relevant in the context of aging and dementia, is assessed in numerous ways-hindering the comparison of findings across studies and settings. Therefore, the present study aimed to link item-level self-report questionnaire data from international aging studies. Method: We harmonized secondary data from 24 studies and 40 different questionnaires with item response theory (IRT) techniques using a graded response model with a Bayesian estimator. We compared item information curves to identify items with high measurement precision at different levels of the self-perceived cognitive functioning latent trait. Data from 53,030 neuropsychologically intact older adults were included, from 13 English language and 11 non-English (or mixed) language studies. Results: We successfully linked all questionnaires and demonstrated that a single-factor structure was reasonable for the latent trait. Items that made the greatest contribution to measurement precision (i.e., "top items") assessed general and specific memory problems and aspects of executive functioning, attention, language, calculation, and visuospatial skills. These top items originated from distinct questionnaires and varied in format, range, time frames, response options, and whether they captured ability and/or change. Conclusions: This was the first study to calibrate self-perceived cognitive functioning data of geographically diverse older adults. The resulting item scores are on the same metric, facilitating joint or pooled analyses across international studies. Results may lead to the development of new self-perceived cognitive functioning questionnaires guided by psychometric properties, content, and other important features of items in our item bank.
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    Sex differences in the genetic architecture of cognitive resilience to Alzheimer's disease
    (Oxford University Press, 2022) Eissman, Jaclyn M.; Dumitrescu, Logan; Mahoney, Emily R.; Smith, Alexandra N.; Mukherjee, Shubhabrata; Lee, Michael L.; Scollard, Phoebe; Choi, Seo Eun; Bush, William S.; Engelman, Corinne D.; Lu, Qiongshi; Fardo, David W.; Trittschuh, Emily H.; Mez, Jesse; Kaczorowski, Catherine C.; Hernandez Saucedo, Hector; Widaman, Keith F.; Buckley, Rachel F.; Properzi, Michael J.; Mormino, Elizabeth C.; Yang, Hyun Sik; Harrison, Theresa M.; Hedden, Trey; Nho, Kwangsik; Andrews, Shea J.; Tommet, Douglas; Hadad, Niran; Sanders, R. Elizabeth; Ruderfer, Douglas M.; Gifford, Katherine A.; Zhong, Xiaoyuan; Raghavan, Neha S.; Vardarajan, Badri N.; Alzheimer’s Disease Neuroimaging Initiative (ADNI); Alzheimer’s Disease Genetics Consortium (ADGC); A4 Study Team; Pericak-Vance, Margaret A.; Farrer, Lindsay A.; Wang, Li San; Cruchaga, Carlos; Schellenberg, Gerard D.; Cox, Nancy J.; Haines, Jonathan L.; Keene, C. Dirk; Saykin, Andrew J.; Larson, Eric B.; Sperling, Reisa A.; Mayeux, Richard; Cuccaro, Michael L.; Bennett, David A.; Schneider, Julie A.; Crane, Paul K.; Jefferson, Angela L.; Hohman, Timothy J.; Radiology and Imaging Sciences, School of Medicine
    Approximately 30% of elderly adults are cognitively unimpaired at time of death despite the presence of Alzheimer's disease neuropathology at autopsy. Studying individuals who are resilient to the cognitive consequences of Alzheimer's disease neuropathology may uncover novel therapeutic targets to treat Alzheimer's disease. It is well established that there are sex differences in response to Alzheimer's disease pathology, and growing evidence suggests that genetic factors may contribute to these differences. Taken together, we sought to elucidate sex-specific genetic drivers of resilience. We extended our recent large scale genomic analysis of resilience in which we harmonized cognitive data across four cohorts of cognitive ageing, in vivo amyloid PET across two cohorts, and autopsy measures of amyloid neuritic plaque burden across two cohorts. These data were leveraged to build robust, continuous resilience phenotypes. With these phenotypes, we performed sex-stratified [n (males) = 2093, n (females) = 2931] and sex-interaction [n (both sexes) = 5024] genome-wide association studies (GWAS), gene and pathway-based tests, and genetic correlation analyses to clarify the variants, genes and molecular pathways that relate to resilience in a sex-specific manner. Estimated among cognitively normal individuals of both sexes, resilience was 20-25% heritable, and when estimated in either sex among cognitively normal individuals, resilience was 15-44% heritable. In our GWAS, we identified a female-specific locus on chromosome 10 [rs827389, β (females) = 0.08, P (females) = 5.76 × 10-09, β (males) = -0.01, P(males) = 0.70, β (interaction) = 0.09, P (interaction) = 1.01 × 10-04] in which the minor allele was associated with higher resilience scores among females. This locus is located within chromatin loops that interact with promoters of genes involved in RNA processing, including GATA3. Finally, our genetic correlation analyses revealed shared genetic architecture between resilience phenotypes and other complex traits, including a female-specific association with frontotemporal dementia and male-specific associations with heart rate variability traits. We also observed opposing associations between sexes for multiple sclerosis, such that more resilient females had a lower genetic susceptibility to multiple sclerosis, and more resilient males had a higher genetic susceptibility to multiple sclerosis. Overall, we identified sex differences in the genetic architecture of resilience, identified a female-specific resilience locus and highlighted numerous sex-specific molecular pathways that may underly resilience to Alzheimer's disease pathology. This study illustrates the need to conduct sex-aware genomic analyses to identify novel targets that are unidentified in sex-agnostic models. Our findings support the theory that the most successful treatment for an individual with Alzheimer's disease may be personalized based on their biological sex and genetic context.