Postpartum anxiety (PPA) affects up to 20% of mothers in the first year after delivery, with mothers often reporting both psychological and physical symptoms. Present non-pharmacological interventions are effective at improving some psychological aspects of PPA such as anxiety, depressive mood, and distress. However, current interventions are not effective in improving emotion regulation (ER), something that many with PPA experience impairment in. Current interventions also seldom target the physical aspects of anxiety, such as bodily awareness - sensing and understanding internal signals in the body (e.g., sensing a fast heartbeat). There is a link between ER and bodily awareness, however psychological interventions that target both these aspects have not been investigated in the PPA population. As a result, a mind-body intervention targeting both ER and bodily awareness is needed to offer a more holistic treatment option.

The purpose of the proposed study is to test the effectiveness of a 4-week mindfulness intervention on anxiety symptoms, ER, and bodily awareness in those with PPA. We will use self-report questionnaires alongside brain imaging (functional magnetic resonance imaging; fMRI) to evaluate the effectiveness. Combining both subjective and objective measures will provide greater confidence in our findings, ensuring a more comprehensive understanding of the intervention's impact. Self-report questionnaires will be administered at enrolment, immediately post-intervention, and 4 weeks post-intervention. Brain imaging will be conducted at enrolment and immediately post-intervention. We believe this intervention will lead to improvements in anxiety symptoms, ER, and bodily awareness on the questionnaires and fMRI scans.

If effective, the proposed mindfulness intervention will target a broader range of psychological and physical symptoms, and reduce the negative impact of PPA on mothers and their infants in Canada and beyond.

Inclusion Criteria:

• mothers/birthing parents 18 years and older who are between 0-12 months postpartum
• principal diagnosis of an anxiety disorder as per the Diagnostic Assessment Research Tool (DART; Schneider et al., 2022), with or without comorbid depression
• no concurrent psychological treatment
• not taking psychoactive medication or a) medications are stable in dose and type for at least 8 weeks prior to the study (as per Canadian psychiatric guidelines; McQueen et al., 2016) and b) medications remain stable throughout the study
• fluent in English, minimal grade 8 reading level.

Exclusion Criteria:

• severe depression/suicidality requiring acute intervention
• women with psychotic or current alcohol or substance use disorders
• suffering from severe claustrophobia
• metallic objects in body (metal implants, pacemakers)
• currently pregnant

Experimental group participants will be given the option to consent to having their de-identified REDCap questionnaires and fMRI scans data shared with the Canadian Biomarker Integration Network in Depression (CAN-BIND). CAN-BIND is a standardized research platform that supports large-scale collaboration by collecting and curating data from both healthy and clinical populations. If one chooses to provide this optional consent, their data may be used to support future ethically approved research projects. All shared data will be encrypted and de-identified to protect privacy as CAN-BIND follows strict ethical and data security standards, comparable to those at St. Joseph's Healthcare Hamilton.