Daily Stress and Vascular Function in Midlife as a Risk Factor for Cognitive Decline

Inclusion Criteria: * Males and females aged 40-55 yrs * Absence of objective cognitive impairment (≥26 on the Montreal Cognitive Assessment) * Absence of diagnosed or unstable neurocognitive, cardiovascular, metabolic, renal, hepatic, autonomic, autoimmune, or dermatological diseases, as determined by medical history, physical examination, blood chemistries, and 12-lead resting electrocardiogram * Participants must have a level of understanding of the English language sufficient to provide informed consent and to agree to all tests and procedures, as well as the capacity and willingness to attend all study related visits and to comply with the study protocol Exclusion Criteria: Subjects will be excluded at the discretion of the PI/collaborating clinicians or for any of the following reasons: * \<40 or \>55 yrs * Psychiatric illness aside from MDD (e.g., bipolar disorder, schizophrenia, eating disorders), assessed by the MINI and self-report * Objective cognitive impairment (\<26 on the Montreal Cognitive Assessment) * Diagnosed or unstable neurocognitive, cardiovascular, metabolic, renal, hepatic, autonomic, autoimmune, or dermatological diseases * Current or recent use (within 8 wks) of medications that alter cardiovascular function or psychoactive/psychopharmacological drugs * Body mass index ≥35 kg/m2 * Resting systolic BP ≥140 mmHg * HbA1c ≥5.7% * Direct low-density lipoprotein ≥160mg/dl * Tobacco use (including electronic cigarettes) * Females who are pregnant, brea…