This is a qualitative research study that will involve individual interviews of ACS patients with elevated depression symptoms (stratified by time since ACS \[≤2 years and \>2 years post ACS\]; N=10 participants per strata) to explore patients' treatment needs and preferences for an adapted MBCT intervention, and barriers and facilitators for future intervention research procedures (i.e., videoconferencing delivery of the intervention and collection of dried blood spots). It will also involve individual interviews of ACS patients without elevated depression symptoms (N=10) to better understand the needs of ACS patients who are interested in treatment but not currently depressed, in order to inform future outreach and treatment development efforts (total N=30). Interviews will be conducted either in person, by phone, or by video conference.

Participants will be recruited in several ways. First, participants will be identified using the MGH Research Patient Data Registry (RPDR). Participants will be pre-screened for eligibility and sent an opt-out letter. Patients will have the option to opt out via phone or email. Patients who do not opt out and meet eligibility requirements will be contacted via phone. Over the phone, patients who express interest in the study will complete an eligibility screen; patients who meet study eligibility criteria will then complete a verbal consent to enroll in the study. Second, patients will be recruited through advertisements (e.g., flyers, brochures) placed throughout inpatient and/or outpatient hospital clinics, community mental health clinics, community businesses (e.g. coffee shops) and social media platforms. The advertisements will ask patients to contact study staff if they are interested in learning more about the study, and the screening procedures will be the same as those described above for RPDR patients. Lastly, patients will be recruited via direct referrals from their providers (e.g., cardiologists, psychiatrists). We will inform providers about the study (e.g., via short presentations at their team meetings) and provide them with advertisement materials to give to their patients. The patients may either contact study staff directly using the information their provider gave them, and/or the provider will contact the study team with the patient's information so that the study team may reach out to the patient. Providers will obtain verbal permission from the patient for the research team to contact them.

Once enrolled, participants will partake in a semi-structured in-person individual interview. Individual interviews will be stratified by time since ACS and depressive symptoms and will explore (a) emotional symptoms; (b) health behavior challenges; (c) specific preferences for the MBCT intervention; and (d) potential barriers and facilitators of group videoconferencing and (e) blood spot data collection. Participants will also complete a survey detailing depression symptoms, trait mindfulness, health behaviors, and other psychological, behavioral, and physical constructs that may potentially be impacted by the MBCT intervention in subsequent trials will be measured. Data collected from the individual interviews will be used to guide MBCT adaptations and research procedures for future clinical trials.