Effort and Appetitive Responding in Depression: Examining Deficits in Motivational and Consummatory Stages of Reward Processing Using the Effort-Doors Task

Depression Remission Over Six Months Characterized by Elevated Target-Locked P300 ERP Component: Prospective Evidence Employing an Affective Visual Oddball Task

Depression is a mental health disorder characterized by dysfunction in cognitive and motivational neural systems. Event-related potential (ERP) research has explored these issues and has found that depression is associated with a reduced P300 ERP component, which likely reflects deficits in processes related to attentional allocation, decision-making, and context updating. However, most of the extant research has employed cross-sectional designs, limiting insight into the temporal precedence between the P300 and depression. Prospective investigations of the P300 and depression association are scarce and would provide further insight into the etiopathology of depression. The present study sought to examine the relationship between baseline P300 amplitude, elicited from an affective visual oddball paradigm, and depression remission after 6 months in a sample of adults (n = 48) suffering from current depressive disorders. Findings indicated that a larger P300 amplitude to target stimuli at baseline was associated with depression remission at the six-month follow-up visit, while no differences were observed for P300 components elicited by the distractor or standard stimuli. The present findings suggest that a reduced P300 amplitude to imperative stimuli may indicate a trait-like neural vulnerability of cognitive and motivational deficits contributing to a greater risk of relapse and a more chronic course of depression. Trial Registration: NCT01941862.

The Go/No-Go P3 and Depressive Symptoms in Adolescents: Trial-Level Change and Mean Amplitude Relate Differently to Anhedonic Versus Negative Mood Symptoms

Prior studies have found an association between reduced P3 brain responses-a neural marker of task engagement-and increased depressive symptoms during adolescence. However, it is unclear whether P3 correlates with depression globally, or with certain facets. Existing depression studies have also typically quantified P3 as a cross-trial average, neglecting possible trial-by-trial effects. Among 72 adolescents (44% female), the current study evaluated relations of distinct depression symptom facets-anhedonia and negative mood-with P3s from a three-stimulus go/no-go task, quantified both in average- and trial-level terms. Although no relationship was evident between overall depressive symptoms and average P3 amplitudes, opposing relations were found for each symptom facet with P3 to frequent and infrequent 'go' stimuli: higher anhedonia predicted smaller P3, whereas increased negative mood predicted larger P3. Single-trial, multilevel modeling analyses clarified these effects by showing reduced P3 across stimuli types at task outset, along with greater trial-to-trial attenuation of P3 to infrequent-go stimuli, for adolescents experiencing greater anhedonia. Conversely, increased negative mood was distinctly related to larger P3 at task onset but was unrelated to amplitude change across trials. Results demonstrate differential relations for anhedonic and negative mood symptoms with P3-indicative of task disengagement versus heightened vigilance, respectively-that may be obscured in analyses focusing on overall depressive symptoms. The divergent associations for anhedonia and negative mood with P3 underscore the need to consider these distinct symptom facets in research aimed at clarifying the nature of neural-circuitry dysfunction in depression.

Multiple risk markers for increases in depression symptoms across two years: Evidence from the reward positivity and the error-related negativity

BACKGROUND

Both a blunted Reward Positivity (RewP) and Error-Related Negativity (ERN) have been associated with depression. Associations between these neural markers and depression have been observed cross-sectionally, but evidence that they can prospectively predict the development of, or increases in, symptoms of depression is more limited.

METHOD

In this study, we collected EEG data from 157 young adults at a baseline visit (T1), using the Doors and Flanker Tasks to elicit the RewP and the ERN respectively. Participants also reported on symptoms of depression at T1, and multiple times across two academic years (T2 - T8).

RESULTS

Using a multilevel model with the RewP and the ERN as predictors, we found that the RewP predicted future symptoms of depression, while controlling for symptoms of depression at T1, such that a blunted RewP at baseline predicted higher depressive symptoms later. In our data, however, the ERN was not a significant predictor of increases in depression symptoms.

CONCLUSIONS

These findings replicate previous work showing the RewP prospectively predicted increases in depression, and further suggest the specificity of this association. Results support the utility of the RewP as a neurophysiological marker that can help clarify the etiology of depression and inform treatment planning.

Aberrant effort-based reward dynamics in anhedonia

Anhedonia is a transdiagnostic symptom and associated with a spectrum of reward deficits among which the motivational dysfunction is poorly understood. Previous studies have established the abnormal cost-benefit trade-off as a contributor to motivational deficits in anhedonia and its relevant psychiatric diseases. However, it remains elusive how the anhedonic neural dynamics underlying reward processing are modulated by effort expenditure. Using an effort-based monetary incentive delay task, the current event-related potential study examined the neural dynamics underlying the effort-reward interplay in anhedonia using a nonclinical sample who scored high or low on an anhedonia questionnaire. We found that effort prospectively decreased reward effect on the contingent variation negativity and the target-P3 but retrospectively enhanced outcome effect on the feedback-P3 following effort expenditure. Compared to the low-anhedonia group, the high-anhedonia group displayed a diminished effort effect on the target-P3 during effort expenditure and an increased effort-enhancement effect for neutral trials during the feedback-P3 period following effort expenditure. Our findings suggest that anhedonia is associated with an inefficient control and motivation allocation along the efforted-based reward dynamics from effort preparation to effort production.

How are irritability and anhedonia symptoms linked? A network approach

BACKGROUND

Anhedonia and irritability are two prevalent symptoms of major depressive disorder (MDD) that predict greater depression severity and poor outcomes, including suicidality. Although both symptoms have been proposed to result from paradoxical reward processing dysfunctions, the interactions between these symptoms remain unclear. Anhedonia is a multifaceted symptom reflecting impairments in multiple dimensions of reward processing (e.g., pleasure, desire, motivation, and effort) across distinct reward types (e.g., food, sensory experiences, social activities, hobbies) that may differentially interact with irritability. This study investigated the complex associations between anhedonia and irritability using network analysis.

METHOD

Participants (N = 448, Mage = 33.29, SD = 14.58) reported their symptoms of irritability on the Brief Irritability Test (Holtzman et al., 2015) and anhedonia (i.e., pleasure, desire, motivation, and effort dimensions across four reward types) on the Dimensional Anhedonia Rating Scale (Rizvi et al., 2015). A regularized Gaussian Graphical Model was built to estimate the network structure between items.

RESULTS

Irritability was negatively related to willingness to expand effort to obtain food/drinks (estimate = -0.18), social activities (-0.13), and hobbies (-0.12) rewards. Irritability was positively associated with a desire for food/drinks (0.12).

LIMITATIONS

Only a small proportion (5.8%) of our sample was clinical and the study design was cross-sectional.

CONCLUSION

A specific link between irritability and the effort dimension of the hedonic response across three reward types was identified. Investigating effort expenditure deficits with experimental paradigms may help us understand the mechanisms underlying the comorbidity between irritability and anhedonia in the context of MDD.

Feedback negativity and feedback-related P3 in individuals at risk for depression: Comparing surface potentials and current source densities

Blunted responses to reward feedback have been linked to major depressive disorder (MDD) and depression risk. Using a monetary incentive delay task (win, loss, break-even), we investigated the impact of family risk for depression and lifetime history of MDD and anxiety disorder with 72-channel electroencephalograms (EEG) recorded from 29 high-risk and 32 low-risk individuals (15-58 years, 30 male). Linked-mastoid surface potentials (ERPs) and their corresponding reference-free current source densities (CSDs) were quantified by temporal principal components analysis (PCA). Each PCA solution revealed a midfrontal feedback negativity (FN; peak around 310 ms) and a posterior feedback-P3 (fb-P3; 380 ms) as two distinct reward processing stages. Unbiased permutation tests and multilevel modeling of component scores revealed greater FN to loss than win and neutral for all stratification groups, confirming FN sensitivity to valence. Likewise, all groups had greater fb-P3 to win and loss than neutral, confirming that fb-P3 indexes motivational salience and allocation of attention. By contrast, group effects were subtle, dependent on data transformation (ERP, CSD), and did not confirm reduced FN or fb-P3 for at-risk individuals. Instead, CSD-based fb-P3 was overall reduced in individuals with than without MDD history, whereas ERP-based fb-P3 was greater for high-risk individuals than for low-risk individuals for monetary, but not neutral outcomes. While the present findings do not support blunted reward processing in depression and depression risk, our side-by-side comparison underscores how the EEG reference choice affects the characterization of subtle group differences, strongly advocating the use of reference-free techniques.

Reward processing in adolescents with social phobia and depression

OBJECTIVE

Impaired reward processing has been found in individuals with anxiety, but also major depressive disorder (MDD). Here, we studied neural correlates of reward anticipation and processing in a sample of youth with severe social phobia and comorbid depression (SP/MDD) and investigated the specific contribution of SP and MDD symptoms.

METHODS

15 affected, unmedicated and 25 typically developing (TD) youth completed a monetary gambling task, which included a positive, negative and ambiguous reward condition. Event-related potentials representing cue processing (cue P300), reward anticipation (stimulus preceding negativity, SPN), reward sensitivity (feedback related negativity, FRN) and reward processing (reward P300) were analysed.

RESULTS

Reduced amplitudes of the right hemispheric (r)SPN and reward P300 were observed in SP/MDD compared to TD. Within the SP/MDD group SP symptoms correlated with larger rSPN, and FRN amplitudes. MDD symptoms correlated with smaller rSPN and smaller FRN positive-negative difference wave.

CONCLUSIONS

Reward anticipation and feedback processing are reduced in SP/MDD. Higher SP symptoms are associated with stronger neural activation during reward anticipation and reward sensitivity. Depressive symptoms are associated with decreased reward anticipation and sensitivity. Findings are in line with the theory of heightened vigilance in anxiety and blunted reward processing due to anhedonia in MDD.

SIGNIFICANCE

The study results can inform behavioural interventions for SP and MDD.