Collected Dataset / VETSA_Baseline

VETSA participants are members of male-male twin pairs (both monozygotic and dizygotic) ranging in age from 51 to 60 years (birth year between 1943 and 1954) at the baseline assessment. These twins are all members of the VET Registry and both served in the American military between 1965-1975. Only men are in the VET Registry. Data include questionnaires, in-person cognitive testing, medical history and health functioning. Subsets of the sample participated in the VETSA MRI longitudinal studies (depending on eligibility for scanning N=515 at baseline) in which structural MRI data were procured; and in the VETSA Neuroendocrine study (2004--2008) in which cortisol, DHEAS, and testosterone were assayed and detailed logs kept (N=783). The VETSA 2 follow-up paralleled the VETSA 1 data collection but did not include neuroendocrine data.

The domains of assessment for VETSA include an extensive neuropsychological test battery, as well as health, personality, and psychosocial indicators, and APOE genotype.

Blood and, in a few cases, buccal cells were also collected for the purpose of genotyping.

Funded by a separate R01, all VETSA 1 participants enrolled from 2005 were automatically part of the VETSA Cortisol/Neuroendocrine study (N=783). 5 saliva samples corresponding to the diurnal cycle were collected on 2 non-consecutive days at home; 7 saliva samples were collected on the in-lab test day (17 samples). Assays were conducted for cortisol, DHEAS, and free testosterone. Participants kept a log at each data point.

Funded by a separate R01, starting in 2005, eligible VETSA 1 participants (final N=515) were enrolled in the VETSA MRI 1 study in which structural brain imaging was performed on using 1.5 T magnet. Eligibility is determined by standard MRI safety protocols.