CBT for Postpartum Depression and Infant Emotion Regulation

Changes in Mother-Infant Synchrony: Physiological and behavioural synchrony patterns are thought to shape infant ER development and explain how treating PPD may exert its effects on infants. Brain-to-brain Synchrony (fNIRS): The fNIRS pre-scanning technique will be used.

The Face-to-Face Stillage Paradigm (FFSP) will be used to observe infant emotion regulatory patterns.

Parent-Child Early Relational Assessment (PCERA) will be used to observe infant emotion regulatory patterns.

One saliva sample will be taken from infants and from mothers at each study visit will be used for epigenetic analyses. Epigenetic modifications will be used to mediate and assess the effect of early life interactions on development.

mPFC Activity (Dense-array functional near-infrared spectroscopy): Measures of oxy- and deoxygenated hemoglobin within the mPFC (medial section of Brodmann areas 9-12 and 25) will be assessed. Hemodynamic activity generated specifically in the mPFC will be acquired using our Gowerlabs® dense array fNIRS system, which utilizes high density diffuse optical tomography (DOT) to produce 3-D images of targeted brain regions and functional connectivity. High density-DOT fNIRS technology yields superior temporal and compatible spatial resolution to fMRI, but without needing to examine infants while sedated or asleep. Adverse mPFC development is one of the most prominent mechanisms underlying later mental disorder risk. Studies examining fNIRS test-retest and are robust to changes in head size. In three pilot dyads, it demonstrated exceptional spatial specificity for infant mPFC activity.

Corticolimbic Brain Activity: Electroencephalographic (EEG) Frontal Alpha Asymmetry (FAA). Portable EEG headbands provide valid EEG activity assessments in adult and infant populations, and do not interfere with fNIRS caps/recordings. These headbands will be used to examine asymmetric patterns of EEG activity over the frontal lobes. These patterns reflect the activity of multiple corticolimbic brain areas underlying affective tendencies and regulatory capacity, including the prefrontal cortex, amygdala, hippocampus, anterior cingulate and insula. Greater relative right FAA in infancy reflects a predisposition to negative emotions and difficulties regulating them, is considered a marker of psychopathology vulnerability and is linked to increased risk for depression and anxiety across the lifespan. Measures of FAA are stable across infancy and into childhood.

PSNS Activity: High-frequency Heart Rate Variability (HF-HRV). HF-HRV, obtained by the Mindware LTD electrocardiogram (ECG), reflects greater flexibility of the PSNS to handle stress and enables infants to utilize social interactions to regulate physiological states. HRV is linked to the integrated activity of multiple brain regions, including the mPFC and amygdala. HRV is an index of coordinated activity in top-down regulatory brain regions and sub-cortical emotion generation networks that serve to guide flexible, adaptive control of behaviour. Low HRV in infancy is among the earliest emerging markers of poor ER and is linked to risk for depression, anxiety and even physical health problems in adulthood. HF-HRV shows robust test-retest reliability across infancy.

Parent-Child Play Task: Birthing parents and their child will be given a 3D puzzle comprised of 7 wooden pieces of different lengths and colours (Castle Logix, Smart Games). The puzzle can be solved in different ways based on a guidebook. Parents will be given the guidebook and asked to instruct the child (using only their words) to design two versions of the puzzle. This task aims to challenge the dyad through a problem solving situation, and assesses dyadic regulation of frustration. The dyad will play with this activity for 5 minutes.

Tower of Patience task: This task will be used to measure frustration and flexible attention regulation. The child and the tester (research assistant) will work together to build a tower out of blocks. They will take turns placing blocks on top of one another. Each time it is the tester's turn to place a block, they will delay their turn by intervals of 10 seconds (i.e., wait 10 seconds to place block one, wait 20 seconds to place block two, wait 30 seconds to place block three, and so on until 8 blocks have been placed or 4 turns have passed).

Pet-Store Stroop Task: Using a touch screen computer, children are tasked with putting animals which had escaped from a pet store back into their cages (bring a dog back to the other dogs). In control conditions, animals are identified by both their appearance and sound (a dog will bark). However, in conditions designed to assess neurobehavioural flexibility, animals will utter the sound of a different species (a dog will say "meow")- and children are required to sort the animal based on the sound, not appearance. This task is sensitive to early emerging higher-order flexibility capacity (shifting attention between competing demands) and activates the PFC brain regions that appear to be affected by exposure to PPD, and that underly ER2. The task takes approximately 5 minutes to complete.

Child behavior Questionnaire Very Short Form (CBQ-VSF): Birthing parents will complete the 36-item CBQ-VSF, which captures three broad dimensions of child temperament, each of which contribute to ER capacity.

Multidimensional Assessment Profile Temper Loss (MAPS-TL) Scale: Children's mothers will complete the 22-item Temper Loss Scale of the MAP, which uses a Likert-Type Scale (never=0, many times per day=6) to assess the intensity and duration of key irritability behaviours, including mood and tantrums (e.g., "gets quite frustrated when prevented from doing something s/he wants to do"). Importantly, this scale is specifically designed to decipher between typical and atypical levels of irritability in early childhood.

Child Behavior Questionnaire (CBCL 1.5-5): The CBCL is a validated, well recognized scale which measures multiple problem behaviours associated with poor ER capacity. Birthing parents will complete this 99-item scale to assess these potential problem behaviours in their child4.

Changes in Mother-Infant Synchrony Brain-to-brain Synchrony (fNIRS): We will use fNIRS hyperscanning techniques to target synchronized right dorsolateral (Brodmann's area 9 and 46) and frontopolar activity (Brodmann's area 10) of the PFC within dyads.

Frontal EEG Asymmetry Synchrony PSNS Synchrony Behavioural Synchrony will be quantified by examining the duration of mismatched emotions and behaviours within dyads during the FFSP paradigm during the free play task at T4.

Maternal Regulatory Parenting: At T4, regulatory parenting (appropriate limit setting, resourcefulness) will be examined using the coding interactive behaviour (CIB) scale during the free play task

Maternal Emotion Regulation: At T4, the Difficulties in Emotion Regulation Scale (DERS) will be used to assess emotion regulation in mothers. This is a 36-item self-report measure that assesses one's ability to understand, accept, and manage their emotions. It assesses difficulties in six areas of emotion regulatory capacity in adults: non-acceptance of negative emotions, inability to engage in goal-directed behaviors when distressed, difficulties with impulse control, lack of awareness of emotional responses, limited access to regulation strategies, and difficulty understanding and clarifying.

The DART will be used to determine probable diagnosis of MDD and GAD.