Study aim
This study aims to establish whether adverse child development can be ameliorated by the treatment of depression in pregnant women in an adequately-powered RCT.
The primary outcome will be emotional and behavioural development measured by the Internalising scale of the CBCL at 24 months. The Internalising scale encompasses symptoms that most closely map to the symptoms of affective and anxiety disorders (anxious/depressed symptoms, social withdrawal, emotional reactivity and somatic complaints). There is good evidence that CBCL scores in early childhood, in particular internalising scores, are predictive of later mental health disorders extending into young adulthood (36); see systematic review by (37).
Study design
This is a multi-centre, parallel, two-group RCT designed to recruit 230 depressed pregnant women with a 1:1 allocation ratio to either CBT or TAU (n = 115 in each condition) within a superiority framework. The design is shown in Fig. 1. This protocol follows the recommendations of Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) (38), Guidelines for Reporting Trial Protocols and Completed Trials Modified Due to the COVID-19 Pandemic and Other Extenuating Circumstances (CONSERVE-SPIRIT extension) (39), and Template for Intervention Description and Replication (TIDieR) (40). The research is being conducted in line with Consolidated Standards of Reporting Trials (CONSORT) standards (41) and the National Statement on Ethical Conduct in Research Involving Humans.
Figure 1: Design of the study
PR = post randomisation
Study setting
We are recruiting women across Australia through study advertisement on a free pregnancy tracking mobile application, Ovia Pregnancy. This application supports expectant mothers by providing them with personalised information relevant to their pregnancy. We are also recruiting at major maternity hospitals in Victoria, Australia; Royal Women’s Hospital, Mercy Health, and Monash Health. The advent of COVID-19 slowed the involvement of maternity hospitals until recently. Strategies for achieving adequate participant enrolment to reach target sample size include periodic adjustment of the Ovia study advertisement and meeting regularly with referrers in maternity hospitals including conductance of educational sessions.
Participants
Participants are adult women who are less than 30 weeks pregnant, diagnosed with a current depressive disorder and gave informed consent to participate in the study.
Eligibility criteria
Eligibility for the study is assessed in two stages; screening and diagnostic assessment.
Screening
Women expressing interest in the study are screened on the basis of the following initial criteria: (1) > 18 of age; (2) ≤ 30 weeks pregnant; (3) not currently receiving treatment for depression or anxiety (medication or psychotherapy); (4) fluent in English; (5) an Edinburgh Postnatal Depression Scale (EPDS: 42) score equal to or greater than 13, a positive response to one of the Whooley Questions (43), or clinical indication.
Women who meet these initial criteria are referred to the study and are contacted by the research team for an Intake call. Informed consent to participate in the study is obtained electronically by the study co-ordinator following the Intake call.
Diagnostic assessment
Following the Intake call, maternal mental health is assessed using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-5 Clinical version-CV (SCID-5-CV: 44) to yield a diagnosis of current major depressive episode or depressive episode with insufficient symptoms.
Women with responses reflecting thoughts of self-harm (based on EPDS Item 10 or the SCID) are asked a series of questions to determine intentionality, lethality, access to means, and history of suicide attempts. Women deemed to be at risk requiring crisis or inpatient management are excluded and referred to receive immediate crisis attention. Our protocol follows the principles described in the New South Wales Framework for Suicide Risk Assessment and Management (45).
Women are included in the study if they meet the above-mentioned initial criteria and a DSM-5 diagnosis of major depressive disorder or ‘depressive episode with insufficient symptoms’ and do not meet one or more of the following exclusion criteria as assessed by SCID-5-CV: a) concurrent major psychiatric disorders (particularly psychotic and bipolar disorders; we do not exclude co-morbid anxiety disorders); b) substance use disorder.
Randomisation
Women diagnosed with a depressive disorder and meeting all other criteria are offered randomisation after all baseline data are collected. Randomisation is completed by the study co-ordinator in a 1:1 ratio to CBT intervention (n = 115) or to TAU (n = 115), using a pre-generated, variable-length, permuted-blocks allocation schedule, stratified by site, with allocation concealment ensured by central, independent administration consistent with CONSORT standards (41). The study uses secure randomisation services provided by the NHMRC Clinical Trials Centre. Given the nature of the psychological intervention, study participants cannot be blinded beyond the point of treatment allocation. Outcome assessments are conducted by psychologists who are kept blind to treatment allocation, and the primary analysis will also be conducted blind to treatment allocation. Unblinding is permissible when risk is indicated at follow up and requires referral to a health professional.
Interventions and comparators
Beating the Blues before Birth CBT Intervention
Participants in the CBT intervention group receive seven individual 1-hour weekly sessions and one couple session (if they do not have a partner they can invite a close person such as a family member or a friend). Initially the sessions were delivered in person and since the advent of COVID-19 via telehealth using a secured platform.
Adapted from our Getting Ahead of Post Natal Depression intervention (46, 47), this antenatal CBT intervention was tailored to address the specific needs of pregnant women concerning issues such as lack of time and physical health with a focus on preparing for transition to parenthood, self-care, and lifestyle. Sessions include psycho-education, activities and discussion on behavioural (Understanding Antenatal Depression & Anxiety, Pleasant Activities, Self-Care & Relaxation in Pregnancy, Assertiveness & Self-esteem) and cognitive strategies (Expectations and Transition to Parenthood, Developing a More Helpful Thinking Style, Challenging My Internal Critic). The couple session provides information and support to partners and includes strategies for effective communication. The final session is focussed on Relapse Prevention. The intervention has proved effective in our previous RCT (22).
Participant booklets and partner booklets, which contain information summarising session content, are provided. The intervention is delivered by psychologists specialising in perinatal mental health and the CBT approach and are trained in the program.
Since 29 November 2018, 366 sessions have been delivered to 51 participants as detailed in the Status section below.
Criteria for discontinuing the intervention
Given this is an antenatal intervention it is discontinued when participants give birth prior to the completion of the 8 sessions, in which case a final single postnatal session is delivered prior to the 3-month post-birth time point.
Treatment Fidelity & Adherence
Psychologists adhere strictly to the detailed protocol and manual ensuring uniform delivery. Following each CBT session, therapists check off the items covered (or re-visited) from the manual and ensure all content is covered as women progress in the treatment. These checklists are closely monitored by the study co-ordinator and to date all session content has been covered apart from exceptional occasions, for example when the participant gave birth unexpectedly. In terms of participants’ adherence to therapy, therapists review the homework tasks completed by participants as part of the session.
Treatment as usual
Participants in this group are referred to their general practitioner (GP) with the results of their clinical assessment and information on study participation. Women may elect to be referred to their midwife or obstetrician. Health professionals are free to treat or to refer to other services/agencies as they judge appropriate, as would normally happen where specialised programs are not available. We have successfully demonstrated the superiority of our specialised CBT intervention compared to TAU as a control condition in several of our previous randomised trials in this area of work (22, 47, 48).
Concomitant care
Although current treatment at the time of enrolment is an exclusion criterion, participation in the study does not preclude women from receiving support at later stages. Thus, women in both groups are free to receive concomitant care as they see appropriate.
Study outcome measures
Self-reported outcome measures were initially collected via paper questionnaires. With the advent of COVID-19 these are now collected via Qualtrics platform (Qualtrics, Inc., WA, USA). To promote participant retention, we provide $20 reimbursement for completing the questionnaires at each follow-up time point and send SMS reminders for data returns; thank you, birthday, and end of year season’s greetings.
The primary outcome is child emotional and behavioural development measured by the Internalising scale of the CBCL (34) at 24 months of age (corrected age for babies born less than 32 weeks gestation). Secondary outcome measures are assessed when children are 3 months, 12 months, and 24 months of age, and contemporaneous maternal measures are collected across all time points (see Table 1). Earlier developmental measures (3 and 12 months) will allow detection of emerging treatment effects. Earlier follow-up time points will also facilitate imputation of missing or censored end-point data in intention-to-treat analyses. All psychometric instruments are validated, reliable and widely used. Clinician-administered and observer-rated measures are collected blind to treatment allocation.
Primary outcome
Child Behaviour Checklist Internalising Scale (CBCL: 34). The Internalising scale of the CBCL at 24 months is the primary outcome. The CBCL is one of the most widely used standardised measures in child psychology for evaluating maladaptive behavioural and emotional problems in children 18 months and older. The Internalising scale encompasses symptoms that most closely map to the symptoms of affective and anxiety disorders (anxious/depressed symptoms, social withdrawal, emotional reactivity and somatic complaints). There is good evidence that CBCL scores in early childhood, in particular internalising scores, are predictive of later mental health disorders (36, 37). Completed by a parent or other caregiver, the CBCL1½-5 contains 99 items, scored 0 = not true, 1 = somewhat true, and 2 = very true or often true, based on the preceding two months, to yield empirically based syndrome scores. The Internalising scale yields a single score calculated as the sum of four syndrome scores (anxious/depressed symptoms, social withdrawal, emotional reactivity, and somatic complaints) and has good-to-excellent internal consistency (alpha = .90), inter-rater agreement (r = .75) and test-retest reliability (r = .85).
Secondary outcomes
Child Behaviour Checklist Externalising Scale (CBCL: 34). The Externalising scale comprises syndrome scores for behaviours related to attention and aggression.
Parent-Child Early Relational Assessment (PCERA: 49), a clinician-rated measure, is based on observations of mother-child behaviours that provides an independent rating of infant behaviour. Videos of a structured task and free play are coded by a trained, blinded observer. All subscale scores demonstrated high levels of internal consistency, with coefficients ranging from .75 to .96. The following eight items measuring child depressed affect, anxiety, hyperactivity, and self-regulation are used in this study: Apathetic/Withdrawn/Depressed Mood, Sober/Serious Mood, Anxious/Tense/Fearful Mood, Attentional abilities, Hyperactivity, Persistence, Impulsivity, and Self-regulation.
Revised Infant Behaviour Questionnaire (IBQ-R: 50). The IBQ-R includes fourteen sub-scales: approach, vocal reactivity, high intensity pleasure, smiling and laughter, activity level, perceptual sensitivity, sadness, distress to limitations, fear, falling reactivity/rate of recovery from distress, low intensity pleasure, cuddliness, duration of orienting, and soothability. The sub-scales have adequate internal consistency (alpha = .71 to .90) and positive inter-rater agreement.
Ages & Stages Questionnaires (ASQ-3, ASQ-SE: 32, 33). The ASQ provides an early, parent-reported evaluation of developmental progress. ASQ-3 sub-scales have good to acceptable internal consistency (alpha = .51 to .87), strong test-retest reliability (r = .75 to .82), and robust inter-rater reliability (r = .43 to .69). ASQ-SE sub-scales have adequate internal consistency (Cronbach’s alpha ranged from .67 to .91). ASQ-SE has test-retest reliability of 94%. Based on the results of our pilot study we chose to focus in this study on the problem solving domain of the ASQ-3 and the communication and self-regulation domains of the ASQ-SE at the 3- and 12-month postnatal time point. At the 24-month time point participants are asked to complete the communication, gross motor, fine motor, and problem solving ASQ-3 domains.
Maternal measures
Structured Clinical Interview for DSM-5 – Clinician Version (SCID-5-CV; 44). Diagnosis of current depressive disorder as an inclusion criterion is determined by a blinded psychologist via this gold-standard psychiatric interview conducted over the telephone. This interview is also used to determine other diagnoses or symptoms set as exclusion criteria (i.e., psychotic symptoms, bipolar disorder and substance use disorder). The tool has excellent inter-rater and test-retest reliability (kappa > .70) (51).
Beck Depression Inventory Revised (BDI-II: 52) is a widely used, well-validated, 21-item clinical measure of severity of depression. The BDI-II has been validated against gold-standard diagnostic criteria in perinatal populations (53).
Beck Anxiety Inventory (BAI: 54) is a 21-item measure of anxiety with well-established properties, including in perinatal populations (53).
Perceived Stress Scale (PSS: 55) is the most widely used psychological instrument for measuring the perception of stress. This scale has acceptable internal consistency (alpha > .70) and test-retest reliability (r > .70) (56).
Parenting Stress Index (PSI: 57) is a validated and well-researched 101-item parent report measure of parent-child relationship functioning and attachment.
Demographic and descriptive data: Data are collected on sample demographics (socio-economic indicators and pregnancy information; e.g., prenatal care, smoking, alcohol use, sleep patterns, history of depression during pregnancy), obstetric and birth information (e.g., birth weight, gestation, major complications), psychosocial factors (e.g., history of mental illness) and resource use (other services/medication accessed between follow-ups). Since January 2021 we have been collecting data on the impact of COVID-19 on maternal mental health, child behavioural development and related issues.
Table 1: Schedule of data collection
Safety monitoring
Maternal mood is monitored through questionnaires at four follow-up time points and also through the SCID at two of these time points. When risk of self-harm is indicated in the BDI-II (54) by either a positive score on item 9 and/or overall score within the severe range, or during the SCID a risk assessment is completed. Participants deemed to be at low-to-moderate risk are referred to their GP and are provided with information on other available supports. Participants deemed to be at high risk are referred to receive immediate crisis attention (45).
Data management
All participants are allocated a confidential trial code. The master coding database is kept in a secure computer drive with access restricted to the lead investigators, trial co-ordinator, and treating psychologist. All de-identified data are entered in a secure computer drive. Data entry is performed by the trial co-ordinator and data checks are performed regularly by the lead investigators. De-identified paper files are stored in locked filing cabinets, accessible only to the research team. Audio recordings of interviews and video recordings of parent-infant interaction are de-identified and are saved in secure computer drives only accessible to the research team. Only collated group data will be presented or published.
Statistical methods
Power & sample size calculations
The study is powered with respect to the primary outcome, the Internalising scale of the CBCL at 24 months. In our pilot data the control group standard deviation (SD) for the Internalising scale was 6.6. For the Internalising scale at 24 months, a between-group (treated vs. non-treated) mean difference of 3.3 points is considered the MCID as it equates to ½ SD difference (58, 59). With SD = 6.6, the required n to detect a mean difference of 3.3 points in the Internalising scale with 80% power at alpha (two-tailed) = .05 is 15.7*(6.6/3.3)*2 = 63 per group. We typically see less than 20% loss to follow-up in our larger perinatal RCTs (48, 60). For caution, we are allowing for a prudent margin of 25% attrition. This yields n* = 63/(1–0.25)2 = 112 which rounds to 115 per group (n = 230 in total).
A sensitivity analysis in G*Power confirms that with n = 230, both moderate and large effects have high reliability of being detected (power > 90%) and small effects will be reliably detected with power = 70%; even in models including up to six covariates. Thus, the study is sufficiently powered to detect the MCID in the primary child outcome (Internalising scale at 24 months).
Statistical analyses
Consistent with CONSORT standards (41), the primary analysis will be by intention-to-treat and will be conducted blind to treatment allocation. Baseline data will be secured prior to treatment allocation, and primary analyses will be executed twice: once using observed data, and once using multiple imputation, provided the assumptions for imputation are met (61). The primary outcome (CBCL Internalising scale) will be analysed first using a 2-sample t-test comparing the intervention and control groups, extended to analysis of covariance (ANCOVA) to control for variation in baseline values. Potentially informative covariates, such as maternal antenatal anxiety, and potential mediators, such as maternal postnatal depression, will also be explored using a general linear model. The impact of the intervention on secondary outcomes, including the Externalising scale of the CBCL, and cognitive and motor development will also be explored using t-tests and ANCOVA. This analytical approach provides a direct and statistically sensitive test of the primary aim. In addition to inferential testing, effect sizes and their associated confidence intervals will be calculated. Finally, univariate logistic regression will be executed to determine any prognostic baseline variables that predict the return or non-return of follow-up data.