Maternal suicidality interacts with blunted reward processing to prospectively predict increases in depressive symptoms in 8-to-14-year-old girls

Reward-Related Brain Activity Mediates the relationship between Decision-Making Deficits and Pediatric Depression Symptom Severity

BACKGROUND

The mechanisms linking neural and behavioral indices of reduced reward sensitivity in depression, particularly in children, remain unclear. Reward positivity (RewP), a neural index of reward processing, has been consistently associated with depression. Separately, recent studies using the drift-diffusion model (DDM) on behavioral data have delineated computational indices of reward sensitivity. Therefore, the present study examined whether RewP is a neural mediator of DDM-based indices of reward processing in predicting pediatric depression across varying levels of symptom severity.

METHODS

A community sample of 166 girls, aged 8 to 14 years, completed two tasks. The first was a reward guessing task from which RewP was computed using electroencephalography; the second was a probabilistic reward-based decision-making task. On this second task, DDM analysis was applied to behavioral data to quantify the efficiency of accumulating reward-related evidence (drift rate) and potential baseline bias (starting point) towards the differently rewarded choices. Depression severity was measured using the self-report Children's Depression Inventory (CDI).

RESULTS

RewP was correlated with drift rate, but not starting point bias, towards the more rewarded choice. Furthermore, RewP completely mediated the association between a slower drift rate towards the more rewarded option and higher depression symptom severity.

CONCLUSION

Our findings suggest that reduced neural sensitivity to reward feedback might be a neural mechanism underscoring behavioral insensitivity to reward in children and adolescents with higher depression symptom severity, offering novel insights into the relationship between neural and computational indices of reward processing in this context.

Drinking alcohol by mid-adolescence is related to reduced reward reactivity: Novel evidence of positive valence system alterations in early initiating female youth

Initiation of alcohol use at younger ages is prognostic of later drinking problems. Reward system dysfunction is theorized to contribute to early initiation and escalation of drinking, but existing evidence supports both hyposensitivity and hypersensitivity as risk-markers; research employing effective indices of reward processing is needed for clarification. The reward positivity (RewP) is a well-established neurophysiological index of hedonic "liking," an important aspect of reward processing. Adult research has yielded conflicting findings, with different studies reporting reduced, enhanced, or null associations of RewP with engagement in or risk for harmful alcohol use. No study has examined relations between RewP and multiple indices of drinking in youth. Here, we examined how RewP measured in a gain/loss feedback task related to self-reported drinking initiation and past-month drinking, when accounting for age along with depression and externalizing symptoms, in 250 mid-adolescent females. Analyses showed that (1) compared to not-yet drinkers, adolescents endorsing drinking initiation responded less strongly to monetary gain (RewP) but not loss feedback (FN), and (2) past-month drinking was unrelated to both RewP and FN magnitude. These findings provide evidence for reduced hedonic "liking" as a concomitant of early drinking initiation in adolescent females and warrant further research with mixed-sex adolescent samples exhibiting greater drinking variability.

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.

Altered serum adiponectin and interleukin-8 levels are associated in the pathophysiology of major depressive disorder: A case-control study

BACKGROUND

Major depressive disorder (MDD) is a complex mental health condition that results in several obstacles including disabilities, loss of productivity, and economic burdens on both patients and society. Etiopathogenesis of MDD involves several factors such as sociodemographic, genetic, and biological determinants. However, any suitable biomarkers for risk assessment of depression have not been established yet. Alterations of cytokine are assumed to be involved in the pathophysiology and severity of the depressive disorder. Therefore, we aimed to evaluate serum adiponectin and interleukin-8 (IL-8) among MDD patients in Bangladesh.

METHODS

We recruited a total of 63 MDD patients and 94 age-sex matched healthy controls (HCs) in the present study. MDD patients were enrolled from a tertiary care teaching hospital, Dhaka, Bangladesh, and HCs from surrounding parts of Dhaka city. A psychiatrist assessed all the study participants following the criteria mentioned in the DSM-5. We applied the Hamilton depression (Ham-D) rating scale to assess the depression severity. Serum adiponectin and IL-8 levels were determined using ELISA kits (BosterBio, USA).

RESULTS

The mean serum concentration of adiponectin was decreased (30.67±4.43 μg/mL vs. 53.81±5.37 μg/mL), and the IL-8 level was increased (160.93±14.84 pg/mL vs. 88.68±6.33 pg/mL) in MDD patients compared to HCs. Sex-specific scatters plot graphs showed the distribution of adiponectin and IL-8 levels with Ham-D scores in MDD patients. Also, ROC curve analysis demonstrated good predictive performances of serum adiponectin and IL-8 for MDD with the area under the curve (AUC) as 0.895 and 0.806, respectively.

CONCLUSION

The present study findings suggest that alterations of serum adiponectin and IL-8 levels in MDD patients might be involved in the disease process. Therefore, we can use these changes of cytokines in serum levels as early risk assessment tools for depression. The present study findings should be considered preliminary. We propose further interventional studies to evaluate the exact role of adiponectin and IL-8 in depression.

Greater Cumulative Lifetime Stressor Exposure Predicts Blunted Reward Positivity in Adolescent Girls Followed for 2 Years

BACKGROUND

Although research has found that life stress is associated with reward-related brain activity, few studies have examined how cumulative stressors occurring over the entire lifetime affect reward processing during adolescence.

METHODS

To address this issue, we investigated how lifetime stressor exposure related to reward processing, indexed by the reward positivity, in 240 adolescent girls between ages 8 and 14 years (mean age = 12.4). Participants were followed for 2 years. They completed a reward task at baseline and follow-up and the Stress and Adversity Inventory at follow-up.

RESULTS

As hypothesized, greater lifetime stressor exposure was related to a blunted reward positivity at the follow-up session while controlling for baseline age, baseline reward positivity, and time between assessments. Furthermore, this association was evident for acute but not chronic lifetime stressors.

CONCLUSIONS

These data suggest that the development of adaptive reward processing may be adversely affected by experiencing major life stressors. The results may thus have implications for understanding how stressors increase risk for psychopathology, such as major depressive disorder.

Anhedonia and Suicide

Suicide is a leading cause of death, and presently, there is no definitive clinical indicator of future suicide behaviors. Anhedonia, a transdiagnostic symptom reflecting diminished ability to experience pleasure, has recently emerged as a risk factor for suicidal thoughts and behaviors (STBs). This overview, therefore, has the following aims. First, prior research relating anhedonia to STBs will be reviewed, with a particular focus on clarifying whether anhedonia is more closely associated with suicidal thoughts versus behaviors. Second, the National Institute of Mental Health's Research Domain Criteria Positive Valence Systems provide a useful heuristic to probe anhedonia across different units of analysis, including clinical symptoms, behaviors, neural mechanisms, and molecular targets. Accordingly, anhedonia-related constructs linked to STBs will be detailed as well as promising next steps for future research. Third, although anhedonia is not directly addressed in leading suicide theories, this review will provide potential inroads to explore anhedonia within diathesis-stress and interpersonal suicide frameworks. Last, novel approaches to treat anhedonia as a means of reducing STBs will be examined.