The goal of this clinical trial is to test the effectiveness of a computerized anxiety sensitivity treatment (CAST) compared to a health education control (HEC) in older adults with mild cognitive impairment (MCI) or mild Alzheimer's Disease and related dementias (ADRD) and their care partners. The main questions it aims to answer are: 1. Efficacy of CAST in reducing anxiety and related symptoms among those with MCI/mild ADRD 2. Efficacy of CAST in reducing care partner burden among care partners of people living with MCI/mild ADRD 3. Explore treatment mechanisms using a multi-modal assessment battery of anxiety sensitivity and anxiety Participants will complete six in-person visits including a baseline assessment, two intervention sessions, and three follow-up assessments at 1, 3, and 6-months posttreatment. Participants will also complete three weeks of ecological momentary assessments (EMAs) for one week prior to intervention, one week between intervention sessions, and one week after intervention. If there is a comparison group: Researchers will compare CAST to HEC to see if CAST reduces anxiety and related symptoms in older adults with MCI/mild ADRD and care partner burden to a greater degree than HEC.