This is a randomized controlled trial with an intervention of Center M compared to treatment as usual. Center M consists of weekly digital one-hour group sessions led by a trained therapist aligned with mindfulness based cognitive therapy. Changes in perinatal depression symptoms will be compared between groups.

The study is a randomized control trial (RCT) with two parallel arms, 1) an intervention arm: Center M added to treatment as usual (TAU), defined as standard prenatal care, and 2) a control arm: TAU, again defined as standard prenatal care. As both groups will be obtaining services through the Center for Women's Health at OHSU, offered standard prenatal care is expected to be similar in both arms. The study will be masked to the PI, Co-I's, consultants, and anyone directly collecting or analyzing study data. Primary prenatal care providers will also be masked to subject assignment. Participant and interventionist masking is not possible due to the nature of the intervention arm. The research coordinator(s), research assistants needing to communicate with research participants about group activities (e.g., responding to logistical emails), and volunteers who support the research coordinator or research assistants with communications regarding groups will also be unmasked. Participants will be randomized by the research coordinator or designated research assistant after eligibility determination and study consent.

The Center M intervention proceeds sequentially with weekly one-hour group sessions led by a trained, masters-level (or equivalent) therapist. Each group will include 3-6 participants. These sessions are conducted digitally via WebEx. Center M session structure aligns with mindfulness based cognitive therapy by including: 1) introduction of a core theme and rationale for how this theme relates to mental well-being (i.e., psychoeducation); 2) teaching core mindfulness (including an emphasis on self-compassion) and CBT skills; 3) facilitating in-session practice of skills (i.e., experiential learning); and 4) reviewing home practice of skills as well as barriers to practice. Sessions are focused on skill development, both through active engagement in practice during group sessions and individual home practice. Center M content teaches skills that increase capability for effectively navigating general life stress and the unique stresses of pregnancy and parenting. It is further designed to increase awareness of early warning signs of perinatal depression to allow for identification of the need for additional resources (including more intensive preventive intervention). The curriculum is designed to be a 'light touch', or minimum necessary intervention that still retains the capacity to prevent perinatal depression. Examples and summaries of the curriculum and accompanying handouts and homework are outlined below and full curriculum, handouts, and homework are available in the IRB documents. The Center M curriculum, handouts and homework follows the parent model MBCT curriculum, with alterations made in direct communication with Sona Dimidjian, PhD, and Sherryl Goodman, PhD, the developers of the parent model. The Center M adaptation has been accomplished with the support and involvement of Drs. Dimidjian and Goodman.

Inclusion Criteria:

• Currently pregnant at ≥ 12 weeks of gestation age (GA)
• ≤ 34 weeks GA at time of Center M intervention initiation
• Receiving prenatal care through the Center for Women's Health at Oregon Health & Science University
• Able to fluently understand, speak and read English
• Available, able and willing to attend online group sessions
• Willing and able to receive home practice materials on an accessible smartphone, tablet or computer
• Residing in Oregon or Washington
• Willingness to participate in either randomization arm

Exclusion Criteria:

• Current or past enrollment in a formal mindfulness-based intervention group
• Score in the "severe" range on the Edinburgh Postnatal Depression Scale (EPDS) (≥ 20) or Patient History Questionnaire (PHQ-9) (≥ 20)

The study will be masked to the PI, Co-I's, consultants, and anyone directly collecting or analyzing study data. Primary prenatal care providers will also be masked to subject assignment. Participant and interventionist masking is not possible due to the nature of the intervention arm. The research coordinator(s), research assistants needing to communicate with research participants about group activities (e.g., responding to logistical emails), and volunteers who support the research coordinator or research assistants with communications regarding groups will also be unmasked. Participants will be randomized by the research coordinator or designated research assistant after eligibility determination and study consent.