Association of Sleep Quality on Memory-Related Executive Functions in Middle Age.

Objectives: Sleep quality affects memory and executive function in older adults, but little is known about its effects in midlife. If it affects cognition in midlife, it may be a modifiable factor for later-life functioning.

Methods: We examined the association between sleep quality and cognition in 1220 middle-aged male twins (age 51-60 years) from the Vietnam Era Twin Study of Aging.

Hippocampal atrophy varies by neuropsychologically defined MCI among men in their 50s.

Objective: In an effort to address earliest detection of mild cognitive impairment (MCI), we examined hippocampal volumes and atrophy in middle-aged men to explore neuroanatomical support for different neuropsychological definitions of MCI.

Methods: 460 men aged 51-60 years underwent neuropsychological testing and MRI. MCI was defined according to five criteria sets.

Genetic complexity of episodic memory: a twin approach to studies of aging.

Episodic memory change is a central issue in cognitive aging, and understanding that process will require elucidation of its genetic underpinnings. A key limiting factor in genetically informed research on memory has been lack of attention to genetic and phenotypic complexity, as if "memory is memory" and all well-validated assessments are essentially equivalent. Here we applied multivariate twin models to data from late-middle-aged participants in the Vietnam Era Twin Study of Aging to examine the genetic architecture of 6 measures from 3 standard neuropsychological tests: the California Verbal Learning Test-2, and Wechsler Memory Scale-III Logical Memory (LM) and Visual Reproductions (VR).

Genetic and Environmental Influences of General Cognitive Ability: Is a valid latent construct?

Despite an extensive literature, the "" construct remains a point of debate. Different models explaining the observed relationships among cognitive tests make distinct assumptions about the role of in relation to those tests and specific cognitive domains. Surprisingly, these different models and their corresponding assumptions are rarely tested against one another.

Post-traumatic stress symptoms and adult attachment: a 24-year longitudinal study.

Objectives: Attachment theory has become a key framework for understanding responses to and consequences of trauma across the life course. We predicted that more severe post-traumatic stress (PTS) symptoms at age 37 years would be associated with insecure attachment at age 55 and with worse PTS symptoms 24 years later at age 61, and that age 55 attachment would mediate the influence of earlier PTS symptoms on later symptoms.

Design: Data on PTS self-reported symptoms were available for 975 community-dwelling participants from the longitudinal Vietnam Era Twin Study of Aging at ages 37 and 61 years.

Imputing observed blood pressure for antihypertensive treatment: impact on population and genetic analyses.

Background: Elevated blood pressure (BP), a heritable risk factor for many age-related disorders, is commonly investigated in population and genetic studies, but antihypertensive use can confound study results. Routine methods to adjust for antihypertensives may not sufficiently account for newer treatment protocols (i.e.

Interaction of APOE genotype and testosterone on episodic memory in middle-aged men.

Age-related changes in testosterone are believed to be a key component of the processes that contribute to cognitive aging in men. The APOE-ε4 allele may interact with testosterone and moderate the hormone's association with cognition. The goals of the present study were to examine the degree to which free testosterone is associated with episodic memory in a community-based sample of middle-aged men, and examine the potential interaction between free testosterone and the APOE-ε4 allele.

Early identification and heritability of mild cognitive impairment.

Background: Identifying mild cognitive impairment (MCI) in midlife could improve early identification of Alzheimer's disease (AD). Also, AD is highly heritable, but the heritability of MCI has not been established. We estimated prevalence rates, association with premorbid general cognitive ability (GCA) and heritability for different definitions of neuropsychologically defined MCI in adults in their 50s.

Conceptual and data-based investigation of genetic influences and brain asymmetry: a twin study of multiple structural phenotypes.

Right-left regional cerebral differences are a feature of the human brain linked to functional abilities, aging, and neurodevelopmental and mental disorders. The role of genetic factors in structural asymmetry has been incompletely studied. We analyzed data from 515 individuals (130 monozygotic twin pairs, 97 dizygotic pairs, and 61 unpaired twins) from the Vietnam Era Twin Study of Aging to answer three questions about genetic determinants of brain structural asymmetry: First, does the magnitude of heritability differ for homologous regions in each hemisphere? Despite adequate power to detect regional differences, heritability estimates were not significantly larger in one hemisphere versus the other, except left > right inferior lateral ventricle heritability.