Annual Research Review: Puberty and the development of anhedonia - considering childhood adversity and inflammation

Longitudinal relationships between social anhedonia and internalizing symptoms in autistic children: results from the Autism Biomarkers Consortium for Clinical Trials

BACKGROUND

Social anhedonia, indicating reduced pleasure from social interaction, is heightened in autistic youth and associated with increased internalizing symptoms transdiagnostically. The stability of social anhedonia over time and its longitudinal impact on internalizing symptoms in autism have never been examined.

METHODS

Participants were 276 autistic children (Mage = 8.60, SDage = 1.65; 211 male) with IQ ≥ 60 (MIQ = 96.74, SDIQ = 18.19). Autism severity was measured using the Autism Diagnostic Observation Schedule, Second Edition. Caregivers completed the Child and Adolescent Symptom Inventory, Fifth Edition (CASI-5) at baseline, 6 weeks, and 6 months. The CASI-5 includes a social anhedonia subscale derived from relevant items across domains. ICC (Intraclass Correlation Coefficient) analysis assessed stability, while cross-lagged panel models examined associations among social anhedonia, depression, and social anxiety across time.

RESULTS

At baseline, social anhedonia correlated with autism severity, as well as parent-reported social anxiety and depression. Social anhedonia showed relative stability (ICC = 0.763) over 6 months, with a significant decline between baseline and 6 weeks (β = -0.52, p < .001). Cross-lagged models revealed a bidirectional relationship between social anhedonia and depression over time, while social anxiety displayed concurrent, but not predictive, associations across time.

CONCLUSIONS

Social anhedonia demonstrated stability over 6 months, suggesting that it may be a relatively stable characteristic in autistic children. Concurrent relationships were observed between social anhedonia and depression, as well as social anxiety and attention-deficit/hyperactivity disorder. Only depression demonstrated a bidirectional longitudinal association with social anhedonia. This bidirectional relationship aligns with developmental models linking early negative social experiences to subsequent internalizing symptoms in autistic children, underscoring the clinical significance of social anhedonia assessment in this population.

Effects of KCNQ potassium channel modulation on ventral tegmental area activity and connectivity in individuals with depression and anhedonia

Up to half of individuals with depression do not respond to first-line treatments, possibly due to a lack of treatment interventions informed by neurobiology. A novel therapeutic approach for depression has recently emerged from translational work targeting aberrant activity of ventral tegmental area (VTA) dopamine neurons via modulation of the KCNQ voltage-gated potassium channels. In this study, individuals with major depressive disorder (MDD) with elevated anhedonia were randomized to five weeks of the KCNQ channel opener, ezogabine (up to 900 mg/day) or placebo. Participants completed functional MRI during a monetary anticipation task and resting-state at baseline and at end-of-treatment. The clinical results were reported previously. Here, we examined VTA activity during monetary anticipation and resting-state functional connectivity between the VTA and the ventromedial prefrontal cortex (mesocortical pathway) and ventral striatum (mesolimbic pathway) at baseline and end-of-treatment. Results indicated a significant drug-by-time interaction in VTA activation during anticipation (F(1,34) = 4.36, p = 0.044), where VTA activation was reduced from pre-to-post ezogabine, compared to placebo. Mesocortical functional connectivity was also higher in depressed participants at baseline compared to a healthy control group (t(56) = 2.68, p = 0.01) and associated with VTA hyper-activity during task-based functional MRI at baseline (R = 0.352, p = 0.033). Mesocortical connectivity was also reduced from pre-to-post ezogabine, compared to placebo (significant drug-by-time interaction, F(1,33) = 4.317, p = 0.046). Together this translational work is consistent with preclinical findings highlighting VTA hyper-activity in depression, and suggesting a mechanism of action for KCNQ channel openers in normalizing this hyper-activity in individuals with both depression and anhedonia.

The Reward Positivity Mediates the Association Between Adverse Childhood Experiences and Anhedonia in Young Adults With Drug-Naïve Major Depressive Disorder

BACKGROUND

Current clinical studies have indicated that major depressive disorder (MDD) concurrent with adverse childhood experiences (ACEs) is associated with greater anhedonia. However, little is known about whether the change in reward sensitivity among young individuals with MDD and ACEs is related to anhedonia.

METHODS

We evaluated anhedonia and ACEs in 86 patients with MDD (31 with no or 1 ACE and 55 with 2 or more ACEs) and 44 healthy control participants. Then, participants completed the Iowa Gambling Task during electroencephalography to measure the reward positivity (RewP) and its difference (ΔRewP; gains minus losses). Furthermore, we constructed a mediation model to assess whether aberrant ΔRewP mediated the relationship between ACEs and anhedonia.

RESULTS

Compared with healthy control participants and MDD patients with no or 1 ACE, MDD patients with 2 or more ACEs had the most severe symptoms of anhedonia and impaired decision making and showed significantly reduced reward sensitivity (most blunted ΔRewP). More importantly, ΔRewP mediated the relationship between ACEs and anhedonia in MDD.

CONCLUSIONS

We found that the ΔRewP partially mediated the association between ACEs and anhedonia in patients with MDD, which provides evidence for the neurobiological basis of abnormal changes in the reward system in MDD individuals with early adverse experiences.

Neural and immune interactions linking early life stress and anhedonia

Early experiences of stress and adversity are associated with blunted reward sensitivity and altered reward learning. Meanwhile, anhedonia is characterized by impairments in reward processing, including motivation, effort, and pleasure. Early life stress (ELS) and anhedonia share psychological, behavioral, and neurobiological correlates, and the system-level interactions that give rise to anhedonia have yet to be fully appreciated. The proposed framework uses a multilevel, multisystem approach to aid in understanding neural-immune interactions that link ELS and anhedonia. The interactions linking anhedonia and ELS presented here include reduced reward sensitivity, alterations in hypothalamic-pituitary-adrenal (HPA) axis response, elevated inflammatory cytokines or physiological markers of stress, and blunted reward circuitry functioning along the mesocorticolimbic pathway. The clinical implications and areas for future research are also discussed. Ultimately, this research may inform the development of more specific and individualized treatments for anhedonia.

Two-year trajectories of anhedonia in adolescents at transdiagnostic risk for severe mental illness: Association with clinical symptoms and brain-symptom links

Anhedonia emerges during adolescence and is characteristic of severe mental illness (SMI). To understand how anhedonia emerges, changes with time, and relates with other symptoms, there is a need to understand patterns of this symptom's course reflecting change or stability-and associations with clinical symptoms and neural reward circuitry in adolescents at risk of SMI. In total, 113 adolescents at low or high familial risk of developing SMI completed clinical measures at up to five time points across 2 years and functional magnetic resonance imaging scanning during a guessing reward task at baseline. Growth curve analysis was used to determine the trajectory of anhedonia across 2 years, including different phases (consummatory and anticipatory) and their association with clinical features (risk status, average suicidal ideation, and average depression across time) and neural activation in response to rewards (ventral striatum and dorsal medial prefrontal cortex). The findings revealed anhedonia decreased across 2 years. Furthermore, lower depression severity was associated with decreases in anhedonia across 2 years. There were no interactions between neural reward activation and anhedonia slopes in predicting clinical features. Exploratory analyses examining latent classes revealed three trajectory classes of anhedonia across phases. While preliminary, in the low and decreasing consummatory anhedonia trajectory class, there was a positive association between neural activation of the right ventral striatum in response to rewards and depression. Certain patterns of anhedonia development could confer risk or resilience for specific types of psychopathologies. The results are preliminary but do highlight the complexity and heterogeneity in anhedonia development. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Understanding the paradox: anhedonia and the unexpected divergence from reward seeking during adolescence - A commentary on Gupta et al. (2024)

Anhedonia is a symptom encompassing reduced or absence of motivation and pleasure that often emerges in adolescence and conveys risk for different mental illnesses and other difficulties. In their review, Gupta, Eckstrand, and Forbes (Journal of Child Psychology and Psychiatry, 2024) present an empirically-based conceptual neurodevelopmental model of anhedonia whereby brain development and pubertal maturation create openness to vulnerability to anhedonia that is influenced by early life adversity and chronic inflammation. This commentary considers anhedonia as a paradox of adolescence given its juxtaposition to the expected developmental milestones of adolescence. It highlights the need to consider anhedonia in terms of both variability and universality of children's experiences and biological development, missed opportunities for social relationships and experiences, and forms and functions of rewards and anhedonia.

Brain alterations in adolescents with first-episode depression who have experienced adverse events: evidence from resting-state functional magnetic resonance imaging

Introduction

Adverse life events constitute primary risk factors for major depressive disorder (MDD), influencing brain function and structure. Adolescents, with their brains undergoing continuous development, are particularly susceptible to enduring impacts of adverse events.

Methods

We investigated differences and correlations among childhood trauma, negative life events, and alterations of brain function in adolescents with first-episode MDD. The study included 23 patients with MDD and 19 healthy controls, aged 10-19 years. All participants underwent resting-state functional magnetic resonance imaging and were assessed using the beck depression inventory, childhood trauma questionnaire, and adolescent self-rating life events checklist.

Results

Compared with healthy controls, participants with first-episode MDD were more likely to have experienced emotional abuse, physical neglect, interpersonal relationship problems, and learning stress (all p' < 0.05). These adverse life events were significantly correlated with alterations in brain functions (all p < 0.05).

Discussion

This study contributes novel evidence on the underlying process between adverse life events, brain function, and depression, emphasizing the significant neurophysiological impact of environmental factors.