Public Health Nurse-Peer Co-Led Group Cognitive Behavioral Therapy for Postpartum Depression

PPD is best conceptualized as a continuous construct with its impact operating across a continuum of severity. The primary outcome is change in PPD symptoms at 9 weeks (i.e., immediately post-treatment). This will be measured using the Edinburgh Postnatal Depression Scale (EPDS), a gold standard measure of PPD symptoms used commonly in research and clinical settings. The EPDS has 10 items scored on a scale 0-3. Scores range from 0-30, with higher scores indicating more severe depression symptoms. The EPDS will be examined as a continuous outcome. Changes in score of 4 or more points is considered clinically meaningful improvement.

We will compare DSM-5-defined major depressive disorder (MDD) using the Mini International Neuropsychiatric Interview (MINI). This interview will be administered by telephone at T2-T3. Symptoms must be present every day or nearly every day for a period of at least 2 weeks and include at least one of: depressed mood most of the day, markedly diminished interest or pleasure in all or almost all activities. There must be a total of five symptoms including the previous two criteria and the following five criteria: significant unintentional weight change or appetite change; insomnia or hypersomnia; psychomotor agitation or retardation; fatigue; feelings of worthlessness or inappropriate or excessive guilt; decreased ability to concentrate or make decisions; recurrent thoughts of death or suicidal ideation.

We will compare DSM-5-defined major depressive disorder (MDD) using the Mini International Neuropsychiatric Interview (MINI). This interview will be administered by telephone at T2-T3. Symptoms must be present every day or nearly every day for a period of at least 2 weeks and include at least one of: depressed mood most of the day, markedly diminished interest or pleasure in all or almost all activities. There must be a total of five symptoms including the previous two criteria and the following five criteria: significant unintentional weight change or appetite change; insomnia or hypersomnia; psychomotor agitation or retardation; fatigue; feelings of worthlessness or inappropriate or excessive guilt; decreased ability to concentrate or make decisions; recurrent thoughts of death or suicidal ideation.

PPD is best conceptualized as a continuous construct with its impact operating across a continuum of severity. The primary outcome is change in PPD symptoms 6 months later (i.e., to assess durability of intervention effects). This will be measured using the Edinburgh Postnatal Depression Scale (EPDS), a gold standard measure of PPD symptoms used commonly in research and clinical settings. The EPDS has 10 items scored on a scale 0-3. Scores range from 0-30, with higher scores indicating more severe depression symptoms. The EPDS will be examined as a continuous outcome. Changes in score of 4 or more points is considered clinically meaningful improvement.

The PSI-SF (Parenting Stress Index-Short Form ) is a 36-item self-scoring measure of parenting stress. It has 3 subscales: Parental distress, parent-child dysfunctional interaction and difficult child. Items are scored on a 5-point Likert scale. Higher scores indicate higher parental stress.

The PSI-SF (Parenting Stress Index-Short Form ) is a 36-item self-scoring measure of parenting stress. It has 3 subscales: Parental distress, parent-child dysfunctional interaction and difficult child. Items are scored on a 5-point Likert scale. Higher scores indicate higher parental stress.

Healthcare resource utilization data will be collected using a questionnaire used in prior work and adapted for the postpartum period based on the Canadian Community Health Survey and Service Use and Resources Form. Participants will be asked to provide information on health care resource use including diagnosis and procedures, medications, hospital stays, physician and ER visits and the use of all other services (including those related to mental health). The investigators will measure resources consumed from the perspective of public health care payer and corresponding unit costs will be calculated using provincial billing rates.

Healthcare resource utilization data will be collected using a questionnaire used in prior work and adapted for the postpartum period based on the Canadian Community Health Survey and Service Use and Resources Form. Participants will be asked to provide information on health care resource use including diagnosis and procedures, medications, hospital stays, physician and ER visits and the use of all other services (including those related to mental health). The investigators will measure resources consumed from the perspective of public health care payer and corresponding unit costs will be calculated using provincial billing rates.

The Mini International Neuropsychiatric Interview (MINI) will be administered at T2 and T3 to provide information on the presence or absence of the major Axis 1 psychiatric disorders in the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM 5) at these time points. This will be administered by phone by a research assistant and will include the following modules: Major Depressive Episode; Major Depressive Disorder; Panic Disorder; Agoraphobia; Social Anxiety Disorder (Social Phobia); Obsessive-Compulsive Disorder; Posttraumatic Stress Disorder; Alcohol Use Disorder; Substance Use Disorder (Non-alcohol); Generalized Anxiety Disorder with extra screening questions for Psychosis.

The Mini International Neuropsychiatric Interview (MINI) will be administered at T2 and T3 to provide information on the presence or absence of the major Axis 1 psychiatric disorders in the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM 5) at these time points. This will be administered by phone by a research assistant and will include the following modules: Major Depressive Episode; Major Depressive Disorder; Panic Disorder; Agoraphobia; Social Anxiety Disorder (Social Phobia); Obsessive-Compulsive Disorder; Posttraumatic Stress Disorder; Alcohol Use Disorder; Substance Use Disorder (Non-alcohol); Generalized Anxiety Disorder with extra screening questions for Psychosis.

The GAD-7 (General Anxiety Disorder-7) is a reliable and valid 7-item self-report scale that assesses the symptoms of generalized anxiety disorder, the most common PPD comorbidity. Total score for the seven items ranges from 0-21 with a higher score indicating more severe anxiety symptoms.

The GAD-7 (General Anxiety Disorder-7) is a reliable and valid 7-item self-report scale that assesses the symptoms of generalized anxiety disorder, the most common PPD comorbidity. Total score for the seven items ranges from 0-21 with a higher score indicating more severe anxiety symptoms.

The MSPSS (Multidimensional Scale of Perceived Social Support) is a 12-item self-report scale designed to measure perceived social support from three sources: family, friends and partner. Each item is rated 1-7 with 1 very strongly disagree and 7 very strongly agree. Higher scores could be considered as having higher levels of support.

The MSPSS (Multidimensional Scale of Perceived Social Support) is a 12-item self-report scale designed to measure perceived social support from three sources: family, friends and partner. Each item is rated 1-7 with 1 very strongly disagree and 7 very strongly agree. Higher scores could be considered as having higher levels of support.

The Infant Behavior Questionnaire - Revised (Very Short Form) is a parent report measure of infant temperament. The IBQ-R (Very Short Form) consists of 37 items answered on a 7-point scale (1-7) and assess 3 factors: Positive Affectivity/Surgency with 13 items, Negative Emotionality with 12 items and Orienting/Regulatory Capacity with 12 items. Higher scores indicate greater alignment with the domain.

The Infant Behavior Questionnaire - Revised (Very Short Form) is a parent report measure of infant temperament. The IBQ-R (Very Short Form) consists of 37 items answered on a 7-point scale (1-7) and assess 3 factors: Positive Affectivity/Surgency with 13 items, Negative Emotionality with 12 items and Orienting/Regulatory Capacity with 12 items. Higher scores indicate greater alignment with the domain.

The PBQ (Postpartum Bonding Questionnaire) is a 25-item maternal report measure that assesses four aspects of maternal-infant relations: (1) bonding, (2) rejection and anger towards the infant, (3) infant-focused anxiety and (4) incipient abuse. Subscales 1-3 will be explored as a continuous outcome using subscale total score. Respondents respond to each statement based on a 6-point scale, with total scale scores ranging from 0-125, with a higher cumulative score indicating more severe bonding disturbances. Each item is scored on a scale of 0-5 with higher scores suggestive of more problems. Mother-infant bonding will be measured as a continuous and dichotomous outcome, using cut-off scores for each subscale indicting bonding disorders. Cutoff values of 12 for the bonding subscale, 17 for rejection and anger, and 10 for infant-focused anxiety have been proposed to define bonding disorders in each category.

The PBQ (Postpartum Bonding Questionnaire) is a 25-item maternal report measure that assesses four aspects of maternal-infant relations: (1) bonding, (2) rejection and anger towards the infant, (3) infant-focused anxiety and (4) incipient abuse. Subscales 1-3 will be explored as a continuous outcome using subscale total score. Respondents respond to each statement based on a 6-point scale, with total scale scores ranging from 0-125, with a higher cumulative score indicating more severe bonding disturbances. Each item is scored on a scale of 0-5 with higher scores suggestive of more problems. Mother-infant bonding will be measured as a continuous and dichotomous outcome, using cut-off scores for each subscale indicting bonding disorders. Cutoff values of 12 for the bonding subscale, 17 for rejection and anger, and 10 for infant-focused anxiety have been proposed to define bonding disorders in each category.

Postpartum Anxiety as a maternal comorbidity is a secondary outcome measure and the DSM-5 defined generalized anxiety disorder (GAD) will be compared using the Mini International Neuropsychiatric Interview (MINI). The GAD module will be part of the full MINI administered during screening and then administered again at T2 and T3 by phone by a research assistant. Excessive worry/anxiety about several routine things must be present most days in the preceding 6 months, anxiety/worry must be difficult to control as well as significantly disrupt social, work or relationship functions or cause significant distress. In order to meet the criteria for a Generalized Anxiety Disorder (current) to be present, three or more of the following must also be present in previous 6 months in addition to the previous three criteria: feel restless, keyed up or on edge; muscle tension; difficulties concentrating; irritability; sleep difficulties.

Postpartum Anxiety as a maternal comorbidity is a secondary outcome measure and the DSM-5 defined generalized anxiety disorder (GAD) will be compared using the Mini International Neuropsychiatric Interview (MINI). The GAD module will be part of the full MINI administered during screening and then administered again at T2 and T3 by phone by a research assistant. Excessive worry/anxiety about several routine things must be present most days in the preceding 6 months, anxiety/worry must be difficult to control as well as significantly disrupt social, work or relationship functions or cause significant distress. In order to meet the criteria for a Generalized Anxiety Disorder (current) to be present, three or more of the following must also be present in previous 6 months in addition to the previous three criteria: feel restless, keyed up or on edge; muscle tension; difficulties concentrating; irritability; sleep difficulties.

A utility-based health-related quality of life self-report instrument consisting of five questions (scale of 1-5) covering mobility, self-care, usual activities, pain/discomfort and depression/anxiety. Lower scores indicate less problems. Quality of Life will be calculated using the Canadian scoring algorithm by multiplying the health utility for the corresponding time period (ie. area under the curve approach)

A utility-based health-related quality of life self-report instrument consisting of five questions (scale of 1-5) covering mobility, self-care, usual activities, pain/discomfort and depression/anxiety. Lower scores indicate less problems. Quality of Life will be calculated using the Canadian scoring algorithm by multiplying the health utility for the corresponding time period (ie. area under the curve approach)

The fidelity with which the PHN/Peers deliver the 9-week CBT intervention will be assessed using measures of adherence and competence that were developed for evaluating delivery of the 9-week CBT groups. Each of the weekly CBT groups will be digitally recorded and trained raters will rate the adherence to the intervention model and competence with which the PHN/Peers deliver the intervention.

The Client Satisfaction Questionnaire-8 (CSQ-8) is an 8-item measure that measures and assesses consumer satisfaction with health and human services. Items are scored on a 4-point scale and total scores range from 8-32, with higher scores indicating greater satisfaction. This will only be completed by participants who complete the 9-week CBT group, immediately after they participate in the intervention.

Study participants will complete this questionnaire at T2 (past 9 weeks) and T3 (past 6 months) answering questions if they received any type of talking therapy or psychotherapy (ie. Cognitive Behavioural Therapy, Group Therapy) other than the group CBT sessions they may have attended as part of the research study. The questions ask about type of therapy received, why it was received, the number of sessions received and the date started and stopped. This information will be used as part of the sub-group analysis to examine the impact of other therapies on the intervention effectiveness.

Study participants will complete this questionnaire at T2 (past 9 weeks) and T3 (past 6 months) answering questions if they received any type of talking therapy or psychotherapy (ie. Cognitive Behavioural Therapy, Group Therapy) other than the group CBT sessions they may have attended as part of the research study. The questions ask about type of therapy received, why it was received, the number of sessions received and the date started and stopped. This information will be used as part of the sub-group analysis to examine the impact of other therapies on the intervention effectiveness.

A 24-item self-report measure of gender identity. We will examine the moderating effect of its instrumentality and expressivity scales, as well as self-identified gender identity on our outcomes

A 24-item self-report measure of gender identity. We will examine the moderating effect of its instrumentality and expressivity scales, as well as self-identified gender identity on our outcomes