Preschool-Onset Major Depressive Disorder is Characterized by Electrocortical Deficits in Processing Pleasant Emotional Pictures

Preschool Mood Disorders: A Review of the Literature from 2017 to 2024

Depression symptoms that onset during early childhood are increasingly recognized as a significant public health concern. A proliferation of research over the last 2 decades has identified preschool depression as a diagnostic reality that is associated with a severe and persistent course of depression throughout the lifespan. The current review summarizes the research on preschool depression from the last 7 years (2017-2024), with a particular focus on the assessment of, factors and outcomes associated with, neurobiological underpinnings of, and treatments for preschool depression. We also discuss potential avenues of inquiry that further elucidate the nature of preschool depression.

Clinical high risk for psychosis syndrome is associated with reduced neural responding to unpleasant images

Deficits in emotion processing are core features of psychotic disorders. Electrophysiology research in schizophrenia suggests deficits in sustained engagement with emotional content (indexed by the late positive potential [LPP]) may contribute to emotion processing impairments. Despite similar behavioral emotion processing dysfunction in those at clinical high risk (CHR) for psychosis, limited research has examined neural mechanisms of impaired emotion processing in the high-risk period, where research can inform risk models. To examine mechanisms of emotion processing deficits in those at CHR for psychosis, the present study used a passive viewing task to elicit the LPP in response to emotionally engaging and neutral stimuli in 28 CHR and 32 control participants (60% female). Relative to controls, CHR participants showed reduced LPP amplitude when viewing unpleasant images (d = 0.75, p = .005) but similar LPP amplitude in response to both neutral (d = 0.35, p = .19) and pleasant images (d = 0.31, p = .24). This pattern suggests that individuals at CHR for psychosis exhibit a deficit in sustained engagement with unpleasant stimuli. Clinical and trait questionnaires were administered to examine potential exploratory explanations for group differences in LPP amplitude. Consistent with evidence suggesting LPP amplitude reflects engagement of approach/avoidance motivational systems, greater LPP amplitude was associated with greater trait-level behavioral avoidance in control participants (r = .42, p = .032) but not CHR participants (r = -.21, p = .40). Together, the present research is consistent with LPP studies in psychosis and implicates reduced sustained engagement with emotional content in the high-risk period. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The impacts of anxiety and depressive symptoms on emotional processing in children and their parents: an event-related potential study

BACKGROUND

Anxiety and depressive symptoms are associated with dysregulated emotional processing. However, less is known about the intra-personal and inter-personal impacts of anxiety and depressive symptoms on emotional processing in children and their parents.

METHODS

In a community sample of 36 parent-child dyads (total N = 72), the current study investigated the intra- and inter-personal effects of anxiety and depressive symptoms on the child's and the parent's neurophysiological responses to emotional (i.e., pleasant and unpleasant) stimuli, indexed by the late positive potential (LPP).

RESULTS

The results indicated that children's anxiety symptoms were correlated with their enhanced LPPs to pleasant versus neutral pictures. Additionally, children's depressive symptoms related to their increased LPPs to unpleasant stimuli. Importantly, children's anxiety symptoms were associated with their parents' increased LPPs to both unpleasant and pleasant information.

CONCLUSIONS

These findings suggest that anxiety symptoms in community children were related to their own as well as their parents' emotional processing. The findings contribute to cognitive and family models of anxiety and depression and further highlight the potential role of dyadic interventions for the alleviation of impairing symptoms in children and their caregivers.

Rethinking the risk for depression using the RDoC: A psychophysiological perspective

Considering that the classical categorical approach to mental disorders does not allow a clear identification of at-risk conditions, the dimensional approach provided by the Research Domain Criteria (RDoC) is useful in the exploration of vulnerability to psychopathology. In the RDoC era, psychophysiological models have an important role in the reconceptualization of mental disorders. Indeed, progress in the study of depression vulnerability has increasingly been informed by psychophysiological models. By adopting an RDoC lens, this narrative review focuses on how psychophysiological models can be used to advance our knowledge of the pathophysiological mechanisms underlying depression vulnerability. Findings from psychophysiological research that explored multiple RDoC domains in populations at-risk for depression are reviewed and discussed. Future directions for the application of psychophysiological research in reaching a more complete understanding of depression vulnerability and, ultimately, improving clinical utility, are presented.

Neural Indicators of Anhedonia: Predictors and Mechanisms of Treatment Change in a Randomized Clinical Trial in Early Childhood Depression

BACKGROUND

Early childhood depression is associated with anhedonia and reduced event-related potential (ERP) responses to rewarding or pleasant stimuli. Whether these neural measures are indicators of target engagement or treatment outcome is not yet known.

METHODS

We measured ERP responses to win and loss feedback in a guessing task and to pleasant versus neutral pictures in young (4.0-6.9 years of age) depressed children before and after randomization to either 18 weeks of Parent-Child Interaction Therapy-Emotion Development (PCIT-ED) or waitlist.

RESULTS

Analyses included reward positivity (RewP) data from 118 children randomly assigned to PCIT-ED (n = 60) or waitlist (n = 58) at baseline and late positive potential (LPP) data from 99 children (44 assigned to PCIT-ED vs. 55 assigned to waitlist) at baseline. Children undergoing PCIT-ED showed a greater reduction in anhedonia (F_1,103 = 10.32, p = .002, partial η² = .09). RewP reward responses increased more (F_1,86 = 5.98, p = .02, partial η² = .07) for PCIT-ED, but a greater change in RewP was not significantly associated with a greater reduction in major depressive disorder symptoms (r = -.12, p > .4). Baseline RewP did not predict treatment change. LPPs to positive pictures did not change across treatment, but greater baseline LPPs to positive pictures predicted a higher likelihood of remission from major depressive disorder in children undergoing PCIT-ED (B = 0.14; SE = 0.07; odds ratio = 1.15; p = .03).

CONCLUSIONS

The ERP reward response improved in young children with depression during a treatment designed to enhance emotion development, providing evidence of target engagement of the neural systems associated with reward. Further, greater baseline LPP responses to positive pictures was associated with a greater likelihood of depression remission, suggesting that this ERP measure can predict which children are most likely to respond to treatment.

Preschool Depression: a Diagnostic Reality

PURPOSE OF REVIEW

We review findings related to predictors, correlates, outcomes, and treatment of preschool depression that have been published in the last 3 years.

RECENT FINDINGS

Preschool depression displays a chronic course through late adolescence and is associated with temperamental and personality traits, poorer physical health, and negative parenting practices. Preschool depression predicts deficits into adolescence, including social difficulties and blunted neural response to rewards. Depressed preschoolers can experience suicidal ideation and behaviors and display an accurate understanding of the finality of death. A treatment for preschool depression has now been validated that uses the parent-child relationship to enhance emotion development and reduce depressive symptoms. Preschool depression is homotypic with depression that occurs later in life. Future work elucidating mechanisms through which preschool depression develops and informs the sub-groups for which particular treatments may be most effective will have considerable implications for prevention and early intervention.

Developmental trajectory of the late positive potential: Using temporal-spatial PCA to characterize within-subject developmental changes in emotional processing

The late positive potential (LPP) is characterized by temporal and spatial changes across development-though existing work has primarily relied on visual or statistical comparisons of relatively few electrodes and averaged activity over time. The current study used an empirically based approach to characterize temporal and spatial changes in ERPs over time. Data were utilized from a large longitudinal study (N = 380) in which the LPP was recorded to pleasant, neutral, and unpleasant pictures around age 9 and again around age 12. Age 9 ERPs were subtracted from age 12 ERPs for all three image types; the resulting ERPs for each subject at each electrode site were then submitted to a temporospatial principal component analysis (PCA). A PCA factor was greater in amplitude for emotional pictures compared to neutral pictures between ages 9 and 12, evident as an occipital negativity and frontocentral positivity that peaked approximately 850 ms following picture presentation. Furthermore, the factor scores to emotional pictures for this component increased as a function of age 12 pubertal development, consistent with the notion that the LPP shifts from occipital to more frontocentral sites in relation to developmental changes from childhood to adolescence. A similar factor was observed when PCA was applied to all ERPs from both ages 9 and 12. Using temporospatial PCA on ERPs collected from the same subjects over time-especially within-subject subtraction-based ERPs-provides a concise way of characterizing and quantifying within-subject developmental changes in both the timing and scalp distribution of ERPs.