Measurement Error and Methodologic Issues in Analyses of the Proportion of Variance Explained in Cognition.

Existing studies examining the predictive ability of biomarkers for cognitive outcomes do not account for variance due to measurement error, which could lead to under-estimates of the proportion of variance explained. We used data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) (N = 1084) to estimate the proportion of variance explained by Alzheimer's disease (AD) imaging biomarkers in four cognitive outcomes: memory, executive functioning, language, and visuospatial functioning. We compared estimates from standard models that do not account for measurement error, and multilevel models that do account for measurement error.

Depression, Vascular Burden, and Dementia Prevalence in Late Middle-Aged and Older Black Adults.

Objectives: Late-life depression and white matter hyperintensities (WMH) have been linked to increased dementia risk. However, there is a dearth of literature examining these relationships in Black adults. We investigated whether depression or WMH volume are associated with a higher likelihood of dementia diagnosis in a sample of late middle-aged to older Black adults, and whether dementia prevalence is highest in individuals with both depression and higher WMH volume.

Be well, sleep well: An examination of directionality between basic psychological needs and subjective sleep among emerging adults at university.

Objectives: The present study assessed bidirectional associations between basic psychological needs and several subjective sleep variables across 2 semesters.

Design: Participants completed an online survey twice (7 months apart) as part of a short-term longitudinal, correlational study.

Participants: Participants were 154 (67.