Mindfulness-Based Cognitive Therapy (MBCT) combines meditation practices from Mindfulness-Based Stress Reduction (MBSR) with cognitive behavioral therapy to improve mental health. Although there is evidence that MBCT provides a variety of mental health benefits, it is particularly designed to prevent depression relapse, which occurs in 80% of people with a history of two episodes of depression. MBCT reduces depression relapse rates by 30%, on average after an eight-week course, and has lower relapse rates than continuing antidepressant medication. However, it is unknown what should be done following the program to optimize its long-term benefit. The investigators plan to conduct a pilot study in preparation for larger-scale clinical trial to determine the most effective maintenance approaches once MBCT has ended. The investigators gathered stakeholder input from MBCT graduates and MBCT teachers to inform the development of maintenance programs for MBCT. From this the investigators formulated several components of a maintenance program for MBCT. This includes providing a booster course for people who have already completed the MBCT program. This will be delivered as a 4-week course, meeting weekly, followed by monthly sessions to help participants build self-efficacy and agency with regard to creating their own plan for relapse prevention. This booster course is adapted from a 12-week program developed by Dr. Willem Kuyken at the Oxford Centre for Mindfulness. The team is planning the following sessions: 1 Deepening mindfulness with a focus on interoceptive awareness. 2) Hedonic system: Appreciating the light within. This would focus on positive emotion. 3) Responding not reacting 4) Two themes: taking care of ourselves, taking care of others. Integrating lessons into daily life with regards to sleep, diet, healthy relationships, behavioral activation. The study will also provide monthly follow-up sessions. The current study is a pilot study aimed at refining the intervention, providing initial data on acceptability and feasibility, and preliminary use of outcome measures in the context of the proposed study design.

The current study is a pilot study aimed at refining a maintenance program for MBCT program graduates. It will provide initial data on acceptability and feasibility, and preliminary use of outcome measures in the context of the proposed study design. The first study group aims to have 10 - 15 participants and will be single arm, with the aim of getting feedback to refine the intervention program. The second study group will aim to enroll between 15 and 30 participants, who will be randomized to receive the intervention program or to a wait-list control group (who will receive the 4-week course 4 months later).

Intervention program: The intervention program will have three components that research subjects will be asked to participate in:

Four-week course to strengthen and extend skills learned in 8-week MBCT course. This will consist of four 2-hour sessions, occurring weekly for four weeks. They will cover content that builds on the original 8-week course. These will be led by an experienced teacher trained in leading MBCT courses with a background in mental health. Sessions will be conducted on a video conferencing platform (Zoom). As part of the course, participants will be asked to develop their own depression relapse plan that describes actions they can take that will be helpful if they are becoming depressed.

Monthly 1.5 hour meeting sessions. These will be led by an experienced MBCT teacher and will consist of a group meditation practice, a check-in time, and discussion of a topic relevant to the MBSR course. The monthly sessions will continue for a minimum of 3 months after the end of the last four-week course. Participants from the different four-week courses will join the same monthly meeting sessions. The investigators anticipate that the 2nd four-week course will start about 4 months after the first course, so that participants in the first group will have about 7 monthly meeting sessions.

Monthly check-in survey. This will be a brief (5 - 10 minute) survey (using Qualtrics) with questions about mood (Patient-Reported Outcomes Measurement Information System {PROMIS} Depression and Positive Affect scales) and recent meditation practice. For participants with elevated depression scores, trained study staff will send an email with the participant's earlier depression relapse plan as a reminder, and set a time to check-in with the participant by phone or Zoom to see how they are doing. If indicated, staff can arrange a brief (15 minutes or less) check-in with the monthly session MBCT teacher to go over current steps to prevent depression relapse.

For each of these steps, staff will follow-up with reminders/check-ins if participants unexpectedly miss sessions of the four-week course or monthly meetings, or do not complete the monthly check-in survey. Participants can opt-out at any time if they do not want reminders/check-ins.

Enrollment visit: Participants who may be eligible based on screening survey will be invited to schedule a Zoom visit with study staff to determine final eligibility (primarily rule out high risk fo suicide), learn more about what study participation involves, and review the study consent form. If there are any concerns that arise during this visit, participants will potentially be referred to the Project Director, Dr. Patty Moran, for additional assessment of issues such as suitability for a group intervention.

Baseline and Follow-up Questionnaires: Participants will complete a study questionnaire at baseline (before starting the four-week course), 1 month (end of course), and every 3 months thereafter as long as monthly meetings sessions are occurring for the study ( anticipated to be at 4 months from study start for both groups and 8 months if in the first four-week course). The questionnaire will include standardized measures of decentering, ruminative/repetitive thought, mindfulness, and self-compassion. At follow-up it will include feedback.

Possible Focus Group/Exit Interview: Participants may be invited to participate in an interview or focus group to provide additional feedback about their experience in the program. Interviews and focus groups will take place over Zoom.

Inclusion Criteria:

1. Age 18+
2. Previously completed MBCT program.
3. A main reason (per self-report) for taking MBCT was for depression

5. Have smartphone or other device for attending virtual classes 6. Ability to speak and read English 7. Lives in US

Exclusion Criteria:

1. Patient Health Questionnaire 8 (PHQ8) score >14 or 5+ items endorsed "more than half the days" or more, one of which corresponds to Question #1 or #2 (generally regarded as indicative of current Major Depressive Disorder).
2. High current risk of suicide on Columbia-Suicide Severity Rating Scale (CSSR-S) or history of attempt in past year
3. Unable or unwilling to attend Zoom group-based sessions as scheduled
4. History of Bipolar 1 disorder, Psychosis or Schizophrenia, or Borderline Personality disorder
5. Substance use, mental health, or other condition that in the opinion of the investigators will make participation in a group setting difficult.