The motivation and pleasure dimension of negative symptoms: neural substrates and behavioral outputs

Abnormal hedonic process in patients with stable schizophrenia: Relationships to negative symptoms and social functioning

Background

Anhedonia is a deficit of dynamic reward process, and a large proportion of schizophrenia patients continue to experience anhedonia even during the stable phase. However, few studies have examined the multiple aspects of performance in reward processing in patients with stable schizophrenia and evidence suggests that physical and cognitive effort may involve different neural mechanisms.

Methods

Parallel measures of effort-based expenditure for reward tasks (EEfRT) and self-report questionnaires of pleasure were applied in 61 patients with stable schizophrenia (SSZ) and 46 healthy controls (HCs), and percentages of hard task choices (HTC%) were used to assess motivation in reward processing. Negative symptoms, neurocognitive and social function were evaluated in SSZ patients, and associations with performance in reward tasks were explored.

Results

SSZ patients reported more severe consummatory and anticipatory anhedonia and social anhedonia. HTC% in reward tasks of SSZ patients were significantly lower than that of HCs, especially in cognitive-effort tasks. HTC% in cognitive tasks were correlated with motivation and pleasure dimension of negative symptoms, whereas HTC% in physical tasks were associated with expression dimension. Anticipatory anhedonia and negative symptoms were correlated with Personal and Social Performance Scale (PSP) scores.

Conclusion

Patients with stable schizophrenia have social anhedonia, physically consummatory and anticipatory anhedonia and reduced reward motivation. They are less willing to make cognitive effort than physical effort for reward. The different associations of physical and cognitive effort with negative symptoms indicate physical and cognitive effort may represent disparate neuropsychological processes. Anticipatory anhedonia is closely related to social functioning.

Differential manifestations of anhedonia in people with social anhedonia and subsyndromal depression

Empirical findings suggested that anhedonia, a reduced capability to access pleasure and a core symptom in both schizophrenia and the major depressive disorder, can be present in people with high levels of social anhedonia and people with subsyndromal depression. Few studies have adopted a multidimensional framework to investigate anhedonia in these subclinical samples. We recruited 35 participants with high social anhedonia (SA), 53 participants with subsyndromal depression (SD), 20 participants with co-occurrence of both traits (CO), and 47 participants with low levels of both traits (CN) to complete a self-report questionnaire capturing the pleasure experience, and the Monetary Incentives Delay (MID) Task and the Social Incentives Delay (SID) Task capturing the motivation of reward. Results indicated that people with SA, SD and CO exhibited lower abstract anticipatory pleasure compared to CN. Moreover, people with SD and CO exhibited specific impairment in response to social incentives. Together, our findings characterized the multidimensional features of anhedonia performances of subclinical samples with SA, SD and CO, which may contribute to the formulation of early identification of at-risk groups.

Global reward processing deficits predict negative symptoms transdiagnostically and transphasically in a severe mental illness-spectrum sample

Reward processing impairments are a key factor associated with negative symptoms in those with severe mental illnesses. However, past findings are inconsistent regarding which reward processing components are impaired and most strongly linked to negative symptoms. The current study examined the hypothesis that these mixed findings may be the result of multiple reward processing pathways (i.e., equifinality) to negative symptoms that cut across diagnostic boundaries and phases of illness. Participants included healthy controls (n = 100) who served as a reference sample and a severe mental illness-spectrum sample (n = 92) that included psychotic-like experiences, clinical high-risk for psychosis, bipolar disorder, and schizophrenia participants. All participants completed tasks measuring four RDoC Positive Valence System constructs: value representation, reinforcement learning, effort-cost computation, and hedonic reactivity. A k-means cluster analysis of the severe mental illness-spectrum samples identified three clusters with differential reward processing profiles that were characterized by: (1) global reward processing deficits (22.8%), (2) selective impairments in hedonic reactivity alone (40.2%), and (3) preserved reward processing (37%). Elevated negative symptoms were only observed in the global reward processing cluster. All clusters contained participants from each clinical group, and the distribution of these groups did not significantly differ among the clusters. Findings identified one pathway contributing to negative symptoms that was transdiagnostic and transphasic. Future work further characterizing divergent pathways to negative symptoms may help to improve symptom trajectories and personalized treatments.

Anhedonia Across and Beyond the Schizophrenia Spectrum

Anhedonia refers to the diminished ability to experience pleasure, and is a core feature of schizophrenia (SCZ). The neurocognitive and neural correlates of anhedonia remain elusive. Based on several influential theoretical models for negative symptoms, this selective review proposed four important neurocognitive domains, which may unveil the neurobiological mechanisms of anhedonia. The authors critically reviewed the current evidence regarding value representation of reward, prospection, emotion-behavior decoupling, and belief updating in the Chinese setting, covering both behavioral and neuroimaging research. We observed a limited application of the transdiagnostic approach in previous studies on the four domains, and the lack of adequate measures to tap into the expressivity deficit in SCZ. Despite many behavioral paradigms for these four domains utilized both social and non-social stimuli, previous studies seldom focused on the social-versus-non-social differentiation. We further advocated several important directions for future research.

Approach and withdrawal from cognitively effortful activities: Development, validation, and transdiagnostic clinical utility of a cognitive motivation scale

BACKGROUND

Deficits in cognition and motivation predict functioning in depressive and psychotic disorders. However, experimental tasks of cognitive motivation are inconsistently correlated with functioning, time-intensive, and not intuitive in clinical practice. We aimed to develop and validate a self-report instrument to assess motivation processes pertinent to engagement with cognitive activities in daily life.

METHOD

Following item generation, scale dimensionality, reliability, and validity were evaluated iteratively over Studies 1-3 with online general adult participants (n1 = 205; n2 = 235; n3 = 181). The 20-item Cognitive Motivation scale was also validated in a Study 3 sub-sample reporting high levels of depressive symptoms (n = 74) and Study 4 early psychosis outpatients (n = 25).

RESULTS

Two-factor model of cognitive approach and cognitive withdrawal, each with good internal consistency, convergent validity, discriminant validity was supported. Cognitive withdrawal showed stronger associations with cognitive difficulties, depressive symptoms, and functional impairments than traditional motivation scale. Participants reporting high depression levels showed more severe difficulties with cognitive motivation than participants reporting low depression levels. In early psychosis outpatients, correlations with functioning and cognitive effort expenditure provided support for scale validity.

LIMITATIONS

Cross-sectional data collection restricted evaluation of repeated administration psychometric properties. Scale validation was mostly established in online community samples and a small patient sample during the COVID-19 pandemic, thereby limiting generalizability of clinical applications.

CONCLUSIONS

Cognitive Motivation scale is a promising tool for future intervention trials seeking to target motivational processes associated with functioning in the general population and potentially across patient groups with amotivation symptoms.

Dampened motivation in schizophrenia: evidence from a novel effort-based decision-making task in social scenarios

Apathy represents a significant manifestation of negative symptoms within individuals diagnosed with schizophrenia (SCZ) and exerts a profound impact on their social relationships. However, the specific implications of this motivational deficit in social scenarios have yet to be fully elucidated. The present study aimed to examine effort-based decision-making in social scenarios and its relation to apathy symptoms in SCZ patients. We initially recruited a group of 50 healthy participants (16 males) to assess the validity of the paradigm. Subsequently, we recruited 45 individuals diagnosed with SCZ (24 males) and 49 demographically-matched healthy controls (HC, 25 males) for the main study. The Mock Job Interview Task was developed to measure effort-based decision-making in social scenarios. The proportion of hard-task choice and a range of subjective ratings were obtained to examine potential between-group differences. SCZ patients were less likely than HC to choose the hard task with strict interviewers, and this group difference was significant when the hard-task reward value was medium and high. More severe apathy symptoms were significantly correlated with an overall reduced likelihood of making a hard-task choice. When dividing the jobs into two categories based on the levels of social engagement needed, SCZ patients were less willing to expend effort to pursue a potential offer for jobs requiring higher social engagement. Our findings indicated impaired effort-based decision-making in SCZ can be generalized from the monetary/nonsocial to a more ecologically social dimension. Our findings affirm the critical role of aberrant effort allocation on negative symptoms, and may facilitate the development of targeted clinical interventions.

Assessing the Link Between General Causality Orientations and Problem Gambling, and the Mediational Role of Nonattachment, Greed, and Anhedonia

Gambling is common in the US, yet nearly one in three players experience gambling-related problems. Using Self-Determination Theory, this study explores how three causality orientations-autonomous, controlled, and impersonal-affect the severity of problem gambling. The study further investigates the mediating roles of nonattachment, dispositional greed, and anhedonia to illuminate how these orientations relate to problem gambling. The data from 675 participants (59% male; Mean age = 40.4 years, SD = 12.9) via Amazon's Mechanical Turk were collected following a screening procedure to identify at-risk players. Findings showed that dispositional greed mediated the impact of a controlled orientation on problem gambling severity, while anhedonia mediated the effect of impersonal orientation. Unexpectedly, nonattachment did not explain the effect of autonomous orientation on problem gambling, though a negative association was still observed. This research enhances understanding of how individual differences and causality orientations contribute to problem gambling behavior. The implications are discussed.

Disentangling negative and positive symptoms in schizophrenia and autism spectrum disorder

Autism spectrum disorder (ASD) and schizophrenia (SZ) share traits, especially in social skills and negative symptoms, and to a lesser degree positive symptoms. Differential diagnosis can be challenging and discerning expressive and experiential negative symptoms may provide knowledge with potential diagnostic and functional relevance that can guide treatment. Two exploratory factor analyses (EFA) were conducted to reveal the underlying dimensions of negative and positive symptoms using the Positive and Negative Syndrome Scale (PANSS), the Scale for the Assessment of Positive Symptoms & Negative Symptoms (SAPS/SANS) and the Autism Diagnostic Observation Schedule-Generic (ADOS-G). Three factors emerged from the negative symptom EFA (70.5 % variance): NF1) Expressive Negative; NF2) Experiential Negative; and NF3) Preoccupation, Absorption & Expressive Affective Flattening. Three positive factors emerged (68.6 % variance): PF1) Hallucinations-Delusions; PF2) Grandiosity; and PF3) Thought Disorder-ADOS positive Symptoms. SZ showed higher PF1 scores, and ASD had higher PF3 scores. No differences between groups were observed in the negative factors. Across groups, all negative factors were inversely associated with quality of life. Only NF1 and NF2 and PF1 were detrimentally related to social functioning. A discriminant function analysis using all factors classified correctly 84.4 % of participants, with PF1, NF1 followed by NF2 being the best predictors of diagnosis. Expressive negative followed by Experiential negative symptoms are of diagnostic value independent of and beyond SZ-related positive symptoms and are related with detrimental functioning. Findings confirm the need to distinctively target negative symptoms, and specific SZ-related and ASD-related positive symptoms, and especially the use of several assessment tools for diagnostic classification.

Electrophysiological Correlates of Reward Anticipation in Subjects with Schizophrenia: An ERP Microstate Study

The current study aimed to investigate alterations of event-related potentials (ERPs) microstate during reward anticipation in subjects with schizophrenia (SCZ), and their association with hedonic experience and negative symptoms. EEG data were recorded in thirty SCZ and twenty-three healthy controls (HC) during the monetary incentive delay task in which reward, loss and neutral cues were presented. Microstate analysis and standardized low-resolution electromagnetic tomography (sLORETA) were applied to EEG data. Furthermore, analyses correlating a topographic index (the ERPs score), calculated to quantify brain activation in relationship to the microstate maps, and scales assessing hedonic experience and negative symptoms were performed. Alterations in the first (125.0-187.5 ms) and second (261.7-414.1 ms) anticipatory cue-related microstate classes were observed. In SCZ, reward cues were associated to shorter duration and earlier offset of the first microstate class as compared to the neutral condition. In the second microstate class, the area under the curve was smaller for both reward and loss anticipation cues in SCZ as compared to HC. Furthermore, significant correlations between ERPs scores and the anticipation of pleasure scores were detected, while no significant association was found with negative symptoms. sLORETA analysis showed that hypo-activation of the cingulate cortex, insula, orbitofrontal and parietal cortex was detected in SCZ as compared to HC. Abnormalities in ERPs could be traced already during the early stages of reward processing and were associated with the anticipation of pleasure, suggesting that these dysfunctions might impair effective evaluation of incoming pleasant experiences. Negative symptoms and anhedonia are partially independent results.

Decoding Early Psychoses: Unraveling Stable Microstructural Features Associated With Psychopathology Across Independent Cohorts

BACKGROUND

Patients with early psychosis (EP) (within 3 years after psychosis onset) show significant variability, which makes predicting outcomes challenging. Currently, little evidence exists for stable relationships between neural microstructural properties and symptom profiles across EP diagnoses, which limits the development of early interventions.

METHODS

A data-driven approach, partial least squares correlation, was used across 2 independent datasets to examine multivariate relationships between white matter properties and symptomatology and to identify stable and generalizable signatures in EP. The primary cohort included patients with EP from the Human Connectome Project for Early Psychosis (n = 124). The replication cohort included patients with EP from the Feinstein Institute for Medical Research (n = 78) as part of the MEND (Multimodal Evaluation of Neural Disorders) Project. Both samples included individuals with schizophrenia, schizoaffective disorder, and psychotic mood disorders.

RESULTS

In both cohorts, a significant latent component corresponded to a symptom profile that combined negative symptoms, primarily diminished expression, with specific somatic symptoms. Both latent components captured comprehensive features of white matter disruption, primarily a combination of subcortical and frontal association fibers. Strikingly, the partial least squares model trained on the primary cohort accurately predicted microstructural features and symptoms in the replication cohort. Findings were not driven by diagnosis, medication, or substance use.

CONCLUSIONS

This data-driven transdiagnostic approach revealed a stable and replicable neurobiological signature of microstructural white matter alterations in EP across diagnoses and datasets, showing strong covariance of these alterations with a unique profile of negative and somatic symptoms. These findings suggest the clinical utility of applying data-driven approaches to reveal symptom domains that share neurobiological underpinnings.

Decoding Early Psychoses: Unraveling Stable Microstructural Features Associated with Psychopathology Across Independent Cohorts

Background

Early Psychosis patients (EP, within 3 years after psychosis onset) show significant variability, making outcome predictions challenging. Currently, little evidence exists for stable relationships between neural microstructural properties and symptom profiles across EP diagnoses, limiting the development of early interventions.

Methods

A data-driven approach, Partial Least Squares (PLS) correlation, was used across two independent datasets to examine multivariate relationships between white matter (WM) properties and symptomatology, to identify stable and generalizable signatures in EP. The primary cohort included EP patients from the Human Connectome Project-Early Psychosis (n=124). The replication cohort included EP patients from the Feinstein Institute for Medical Research (n=78). Both samples included individuals with schizophrenia, schizoaffective disorder, and psychotic mood disorders.

Results

In both cohorts, a significant latent component (LC) corresponded to a symptom profile combining negative symptoms, primarily diminished expression, with specific somatic symptoms. Both LCs captured comprehensive features of WM disruption, primarily a combination of subcortical and frontal association fibers. Strikingly, the PLS model trained on the primary cohort accurately predicted microstructural features and symptoms in the replication cohort. Findings were not driven by diagnosis, medication, or substance use.

Conclusions

This data-driven transdiagnostic approach revealed a stable and replicable neurobiological signature of microstructural WM alterations in EP, across diagnoses and datasets, showing a strong covariance of these alterations with a unique profile of negative and somatic symptoms. This finding suggests the clinical utility of applying data-driven approaches to reveal symptom domains that share neurobiological underpinnings.

Physiological paradigm for assessing reward prediction and extinction using cortical direct current potential responses in rats

Anticipating positive outcomes is a core cognitive function in the process of reward prediction. However, no neurophysiological method objectively assesses reward prediction in basic medical research. In the present study, we established a physiological paradigm using cortical direct current (DC) potential responses in rats to assess reward prediction. This paradigm consisted of five daily 1-h sessions with two tones, wherein the rewarded tone was followed by electrical stimulation of the medial forebrain bundle (MFB) scheduled at 1000 ms later, whereas the unrewarded tone was not. On day 1, both tones induced a negative DC shift immediately after auditory responses, persisting up to MFB stimulation. This negative shift progressively increased and peaked on day 4. Starting from day 3, the negative shift from 600 to 1000 ms was significantly larger following the rewarded tone than that following the unrewarded tone. This negative DC shift was particularly prominent in the frontal cortex, suggesting its crucial role in discriminative reward prediction. During the extinction sessions, the shift diminished significantly on extinction day 1. These findings suggest that cortical DC potential is related to reward prediction and could be a valuable tool for evaluating animal models of depression, providing a testing system for anhedonia.

Australian trial of behavioural activation for people with schizophrenia experiencing negative symptoms: a feasibility randomised controlled trial protocol

INTRODUCTION

Negative symptoms are frequently experienced by people with schizophrenia. People with negative symptoms often have impaired social functioning and reduced quality of life. There is some evidence that cognitive-behavioural therapy results in a modest reduction in negative symptoms. Behavioural activation may be an effective alternative treatment for negative symptoms.The study aims to examine the feasibility and acceptability of implementing a behavioural activation trial delivered in three community mental health services in South Australia to support adult consumers experiencing negative symptoms of schizophrenia.

METHOD AND ANALYSIS

This randomised controlled study will recruit a total of 60 consumers aged 18 years or above with mild-moderate negative symptoms of schizophrenia. The consumers will be randomly allocated to receive behavioural activation plus usual mental healthcare or usual mental healthcare alone. The intervention group will receive twelve 30 min sessions of behavioural activation, which will be delivered twice weekly over 6 weeks. In addition, we aim to recruit nine mental health workers from the three rural mental health services who will complete a 10-week online training programme in behavioural activation. Changes in negative symptoms of schizophrenia and depressive symptoms will be assessed at three time points: (a) at baseline, at 6 weeks and 3 month follow-ups. Changes in health-related quality of life (Short Form F36; secondary outcome) will be assessed at two time points: (a) at baseline and (b) immediately at postintervention after 6 weeks. At the end of the trial, interviews will be conducted with purposively selected mental health workers and consumers. Descriptive statistics and thematic analysis will be used to assess feasibility and acceptability.

ETHICS AND DISSEMINATION

The findings from our feasibility study will inform the design of a fully powered randomised controlled trial to test the effectiveness of behavioural activation as a treatment for negative symptoms in schizophrenia. The study protocol was approved by the Central Adelaide Local Health Network Human Research Ethics Committee. The findings from this study will be disseminated through peer-reviewed scientific journals and conferences.

TRIAL REGISTRATION NUMBER

ACTRN12623000348651p.

Development of a multivariate prediction model for antidepressant resistant depression using reward-related predictors

Introduction

Individuals with depression who do not respond to two or more courses of serotonergic antidepressants tend to have greater deficits in reward processing and greater internalizing symptoms, yet there is no validated self-report method to determine the likelihood of treatment resistance based on these symptom dimensions.

Methods

This online case-control study leverages machine learning techniques to identify differences in self-reported anhedonia and internalizing symptom profiles of antidepressant non-responders compared to responders and healthy controls, as an initial proof-of-concept for relating these indicators to medication responsiveness. Random forest classifiers were used to identify a subset from a set of 24 reward predictors that distinguished among serotonergic medication resistant, non-resistant, and non-depressed individuals recruited online (N = 393). Feature selection was implemented to refine model prediction and improve interpretability.

Results

Accuracies for full predictor models ranged from .54 to .71, while feature selected models retained 3-5 predictors and generated accuracies of .42 to .70. Several models performed significantly above chance. Sensitivity for non-responders was greatest after feature selection when compared to only responders, reaching .82 with 3 predictors. The predictors retained from feature selection were then explored using factor analysis at the item level and cluster analysis of the full data to determine empirically driven data structures.

Discussion

Non-responders displayed 3 distinct symptom profiles along internalizing dimensions of anxiety, anhedonia, motivation, and cognitive function. Results should be replicated in a prospective cohort sample for predictive validity; however, this study demonstrates validity for using a limited anhedonia and internalizing self-report instrument for distinguishing between antidepressant resistant and responsive depression profiles.

Aberrant reward learning, but not negative reinforcement learning, is related to depressive symptoms: an attentional perspective

BACKGROUND

Aberrant reward functioning is implicated in depression. While attention precedes behavior and guides higher-order cognitive processes, reward learning from an attentional perspective - the effects of prior reward-learning on subsequent attention allocation - has been mainly overlooked.

METHODS

The present study explored the effects of reward-based attentional learning in depression using two separate, yet complimentary, studies. In study 1, participants with high (HD) and low (LD) levels of depression symptoms were trained to divert their gaze toward one type of stimuli over another using a novel gaze-contingent music reward paradigm - music played when fixating the desired stimulus type and stopped when gazing the alternate one. Attention allocation was assessed before, during, and following training. In study 2, using negative reinforcement, the same attention allocation pattern was trained while substituting the appetitive music reward for gazing the desired stimulus type with the removal of an aversive sound (i.e. white noise).

RESULTS

In study 1 both groups showed the intended shift in attention allocation during training (online reward learning), while generalization of learning at post-training was only evident among LD participants. Conversely, in study 2 both groups showed post-training generalization. Results were maintained when introducing anxiety as a covariate, and when using a more powerful sensitivity analysis. Finally, HD participants showed higher learning speed than LD participants during initial online learning, but only when using negative, not positive, reinforcement.

CONCLUSIONS

Deficient generalization of learning characterizes the attentional system of HD individuals, but only when using reward-based positive reinforcement, not negative reinforcement.

Is it more effective for anhedonia and avolition? A systematic review and meta-analysis of non-invasive brain stimulation interventions for negative symptoms in schizophrenia

BACKGROUND

Noninvasive brain stimulation (NIBS) techniques are a promising tool for treating the negative symptoms of schizophrenia. Growing evidence suggests that different dimensions of negative symptoms have partly distinct underlying pathophysiological mechanisms. Previous randomized controlled trials (RCTs) have shown inconsistent impacts of NIBS across dimensions.

OBJECTIVE

This systematic review and meta-analysis evaluated the effects of NIBS on general negative symptoms, and on specific domains, including blunted affect, alogia, asociality, anhedonia, and avolition.

DATA SOURCES

PubMed, Web of Science, Embase, Cochrane CENTRAL, PsycINFO, OpenGrey, and Clinicaltrials.gov from the first date available to October, 2023.

RESULTS

Among 1049 studies, we identified eight high-quality RCTs. NIBS significantly affects general negative symptoms (SMD = -0.54, 95% CI [-0.88, -0.21]) and all five domains (SMD = -0.32 to -0.63). Among dimensions, better effects have been shown for improvement of avolition (SMD = -0.47, 95% CI [-0.81, -0.13]) and anhedonia (SMD = -0.63, 95% CI [-0.98, -0.28]). Subgroup analyses of studies that applied once daily stimulation or >10 sessions showed significantly reduced negative symptom severity.

CONCLUSION

NIBS exerts distinct effects across multiple dimensions of negative symptom, with treatment effects related to stimulation frequency and total sessions. These results need to be confirmed in dedicated studies.

Using the Beck Depression Inventory to Assess Anhedonia: A Scale Validation Study

Anhedonia is central to several psychological disorders and a frequent target of psychosocial and pharmacological treatments. We evaluated the psychometric properties of two widely used anhedonia measures derived from the Beck Depression Inventory: a 3-item (BDI-Anh3) and a 4-item version (BDI-Anh4). We evaluated these measures in a large undergraduate sample, a community sample, and a clinical sample. Both the BDI-Anh3 and the BDI-Anh4 showed adequate internal consistency, with BDI-Anh4 performing somewhat better, across the three samples. Both measures showed good convergent and discriminant validity, even after controlling for shared variance with other items on the BDI. These findings indicate that both measures have sufficient reliability and validity to support their use by researchers and clinicians.

Evidence for shallow cognitive maps in schizophrenia

Individuals with schizophrenia can have marked deficits in goal-directed decision making. Prominent theories differ in whether schizophrenia (SZ) affects the ability to exert cognitive control, or the motivation to exert control. An alternative explanation is that schizophrenia negatively impacts the formation of cognitive maps, the internal representations of the way the world is structured, necessary for the formation of effective action plans. That is, deficits in decision-making could also arise when goal-directed control and motivation are intact, but used to plan over ill-formed maps. Here, we test the hypothesis that individuals with SZ are impaired in the construction of cognitive maps. We combine a behavioral representational similarity analysis technique with a sequential decision-making task. This enables us to examine how relationships between choice options change when individuals with SZ and healthy age-matched controls build a cognitive map of the task structure. Our results indicate that SZ affects how people represent the structure of the task, focusing more on simpler visual features and less on abstract, higher-order, planning-relevant features. At the same time, we find that SZ were able to display similar performance on this task compared to controls, emphasizing the need for a distinction between cognitive map formation and changes in goal-directed control in understanding cognitive deficits in schizophrenia.

Anhedonia and Delay Discounting: Differing Patterns of Brain-Behavior Relationships in Healthy Control Participants Versus Individuals With Posttraumatic Stress Disorder

BACKGROUND

Anhedonia may contribute to individual differences in delay discounting (DD). In prior work, we found that higher anhedonia was associated with shallower DD in healthy control (HC) participants but steeper DD in individuals with posttraumatic stress disorder (PTSD). In this study, we aimed to directly compare the relationship between anhedonia and DD across groups and to identify functional brain correlates of this interaction.

METHODS

Participants (HC group: n = 23, DSM-5 PTSD group: n = 23) completed a questionnaire assessing anhedonia (Snaith-Hamilton Pleasure Scale [SHAPS]), task-based functional magnetic resonance imaging of decision making including DD, and resting-state functional magnetic resonance imaging. Task-based activity and resting-state functional connectivity were evaluated in reward-related regions that have also been implicated in PTSD (nucleus accumbens [NAcc], right anterior insula).

RESULTS

Higher SHAPS scores were associated with steeper DD in PTSD, but there was no relationship between DD and SHAPS in the HC group. There was a significant group-by-SHAPS interaction for NAcc activity, t31 = 2.92, p = .007: Greater NAcc activity when immediate rewards were chosen was associated with higher SHAPS in the PTSD group but lower SHAPS in the HC group. In resting-state functional connectivity, there was a group-by-SHAPS interaction between the NAcc seed and right parietal and frontal pole clusters.

CONCLUSIONS

These results extend prior findings that anhedonia is associated with steeper DD in PTSD and demonstrate that this behavioral finding occurs in the context of NAcc hyperactivity to immediate rewards and hyperconnectivity in anhedonic individuals with PTSD.

Women with more severe premenstrual syndrome have an enhanced anticipatory reward processing: a magnetoencephalography study

Laboratory studies reveal that young women with premenstrual syndrome (PMS) often exhibit decreased reward processing during the late luteal phase. However, studies based on the self-reports find opposite results (e.g., higher craving for high-sweet-fat food). These differences may lie in the difference between the stimulus used and measuring the different aspects of the reward. The present study was designed to expand previous work by using a classic monetary reward paradigm, simultaneously examining the motivational (i.e., reward anticipation, "wanting") and emotional (i.e., reward outcome, "liking") components of reward processing in women with high premenstrual symptoms (High PMS). College female students in their early twenties with High PMS (n = 20) and low premenstrual symptoms (Low PMS, n = 20) completed a monetary incentive delay task during their late luteal phase when the premenstrual symptoms typically peak. Brain activities in the reward anticipation phase and outcome phase were recorded using the magnetoencephalographic (MEG) imaging technique. No group differences were found in various behavioral measurements. For the MEG results, in the anticipation phase, when High PMS participants were presented with cues that predicted the upcoming monetary gains, they showed higher event-related magnetic fields (ERFs) than when they were presented with neutral non-reward cues. This pattern was reversed in Low PMS participants, as they showed lower reward cue-elicited ERFs than non-reward cue-elicited ones (cluster mass = 2560, cluster size = 891, p = .03, corrected for multiple comparisons), mainly in the right medial orbitofrontal and lateral orbitofrontal cortex (cluster mass = 375, cluster size = 140, p = .03, corrected for multiple comparisons). More importantly, women with High PMS had an overall significantly higher level of ERFs than women with Low PMS (cluster mass = 8039, cluster size = 2937, p = .0009, corrected for multiple comparisons) in the bilateral precentral gyrus, right postcentral gyrus, and left superior temporal gyrus (right: cluster mass = 410, cluster size = 128, p = .03; left: cluster mass = 352, cluster size = 98, p = .05; corrected for multiple comparisons). In the outcome phase, women with High PMS showed significantly lower theta power than the Low PMS ones for the expected non-reward feedback in the bilateral temporal-parietal regions (cluster mass = 47620, cluster size = 18308, p = .01, corrected for multiple comparisons). These findings reveal that the severity of PMS might alter reward anticipation. Specifically, women with High PMS displayed increased brain activities to reward-predicting cues and increased action preparation after the cues appear.

Environmental context predicts state fluctuations in negative symptoms in youth at clinical high risk for psychosis

BACKGROUND

Negative symptoms (avolition, anhedonia, asociality) are a prevalent symptom in those across the psychosis-spectrum and also occur at subclinical levels in the general population. Recent work has begun to examine how environmental contexts (e.g. locations) influence negative symptoms. However, limited work has evaluated how environments may contribute to negative symptoms among youth at clinical high risk for psychosis (CHR). The current study uses Ecological Momentary Assessment to assess how four environmental contexts (locations, activities, social interactions, social interaction method) impact state fluctuations in negative symptoms in CHR and healthy control (CN) participants.

METHODS

CHR youth (n = 116) and CN (n = 61) completed 8 daily surveys for 6 days assessing negative symptoms and contexts.

RESULTS

Mixed-effects modeling demonstrated that negative symptoms largely varied across contexts in both groups. CHR participants had higher negative symptoms than CN participants in most contexts, but groups had similar symptom reductions during recreational activities and phone call interactions. Among CHR participants, negative symptoms were elevated in several contexts, including studying/working, commuting, eating, running errands, and being at home.

CONCLUSIONS

Results demonstrate that negative symptoms dynamically change across some contexts in CHR participants. Negative symptoms were more intact in some contexts, while other contexts, notably some used to promote functional recovery, may exacerbate negative symptoms in CHR. Findings suggest that environmental factors should be considered when understanding state fluctuations in negative symptoms among those at CHR participants.

Reinforcement learning profiles and negative symptoms across chronic and clinical high-risk phases of psychotic illness

Negative symptoms are prominent in individuals with schizophrenia (SZ) and youth at clinical high-risk for psychosis (CHR). In SZ, negative symptoms are linked to reinforcement learning (RL) dysfunction; however, previous research suggests implicit RL remains intact. It is unknown whether implicit RL is preserved in the CHR phase where negative symptom mechanisms are unclear, knowledge of which may assist in developing early identification and prevention methods. Participants from two studies completed an implicit RL task: Study 1 included 53 SZ individuals and 54 healthy controls (HC); Study 2 included 26 CHR youth and 23 HCs. Bias trajectories reflecting implicit RL were compared between groups and correlations with negative symptoms were examined. Cluster analysis investigated RL profiles across the combined samples. Implicit RL was comparable between HC and their corresponding SZ and CHR groups. However, cluster analysis was able to parse performance heterogeneity across diagnostic boundaries into two distinct RL profiles: a Positive/Early Learning cluster (65% of participants) with positive bias scores increasing from the first to second task block, and a Negative/Late Learning cluster (35% of participants) with negative bias scores increasing from the second to third block. Clusters did not differ in the proportion of CHR vs. SZ cases; however, the Negative/Late Learning cluster had more severe negative symptoms. Although implicit RL is intact in CHR similar to SZ, distinct implicit RL phenotypic profiles with elevated negative symptoms were identified trans-phasically, suggesting distinct reward-processing mechanisms can contribute to negative symptoms independent of phases of illness.

Effort-based decision-making as a determinant of supported employment outcomes in psychotic disorders

Schizophrenia is associated with a heavy economic burden in the United States that is partly due to the high rates of chronic unemployment. Individual Placement and Support (IPS) is an evidenced-based type of supported employment that can improve job obtainment and work outcomes in psychotic disorders. Outcomes vary widely and a persistent challenge for IPS is low levels of engagement in the initial job search phase. Past studies have focused on interview-based motivation deficits as a key determinant of poor treatment engagement and work outcomes in schizophrenia. New validated performance-based measures of motivation, including effort-based decision-making (EBDM) tasks, may explain supported employment outcomes and provide insights into individual differences in IPS outcomes. This study investigated the degree to which IPS engagement (i.e., number of sessions attended during the first four months of service delivery) was related to baseline interview-based motivation deficits and performance on three EBDM tasks - two tasks of physical effort and one of cognitive effort (i.e., Balloon Task, Effort Expenditure for Rewards Task, Deck Choice Effort Task) - in a sample (N = 47) of people with a psychotic disorder. Results indicated that the level of EBDM performance, specifically on the Balloon Task, predicted IPS engagement, accounting for an additional 17 % of the variance above and beyond interview-based motivation deficits (total R2 = 24 %). Overall, these findings suggest that addressing motivational deficits in effort-based decision-making may be beneficial to IPS engagement, which in turn may improve the trajectory of work outcomes.

The Effects of Remote Cognitive Training Combined With a Mobile App Intervention on Psychosis: Double-Blind Randomized Controlled Trial

BACKGROUND

Impairments in cognition and motivation are core features of psychosis and strong predictors of social and occupational functioning. Accumulating evidence indicates that cognitive deficits in psychosis can be improved by computer-based cognitive training programs; however, barriers include access and adherence to cognitive training exercises. Limited evidence-based methods have been established to enhance motivated behavior. In this study, we tested the effects of web-based targeted cognitive and social cognitive training (TCT) delivered in conjunction with an innovative digital smartphone app called Personalized Real-Time Intervention for Motivational Enhancement (PRIME). The PRIME app provides users with a motivational coach to set personalized goals and secure social networking for peer support.

OBJECTIVE

This study investigated whether deficits in cognition and motivation in people with a psychosis spectrum disorder (N=100) can be successfully addressed with 30 hours of TCT+PRIME as compared with 30 hours of a computer games control condition (CG) plus PRIME (CG+PRIME). Here, we describe our study procedures, the feasibility and acceptability of the intervention, and the results on all primary outcomes.

METHODS

In this double-blind randomized controlled trial, English-speaking participants completed all cognitive training, PRIME activities, and assessments remotely. Participants completed a diagnostic interview and remote cognitive, clinical, and self-report measures at baseline, posttraining, and at a 6-month follow-up.

RESULTS

This study included participants from 27 states across the United States and 8 countries worldwide. The study population was 58% (58/100) female, with a mean age of 33.77 (SD 10.70) years. On average, participants completed more than half of the cognitive training regimen (mean 18.58, SD 12.47 hours of training), and logged into the PRIME app 4.71 (SD 1.58) times per week. The attrition rate of 22% (22/100) was lower than that reported in our previous studies on remote cognitive training. The total sample showed significant gains in global cognition (P=.03) and attention (P<.001). The TCT+PRIME participants showed significantly greater gains in emotion recognition (P<.001) and global cognition at the trend level (P=.09), although this was not statistically significant, relative to the CG+PRIME participants. The total sample also showed significant improvements on multiple indices of motivation (P=.02-0.05), in depression (P=.04), in positive symptoms (P=.04), and in negative symptoms at a trend level (P=.09), although this was not statistically significant. Satisfaction with the PRIME app was rated at 7.74 (SD 2.05) on a scale of 1 to 10, with higher values indicating more satisfaction.

CONCLUSIONS

These results demonstrate the feasibility and acceptability of remote cognitive training combined with the PRIME app and that this intervention can improve cognition, motivation, and symptoms in individuals with psychosis. TCT+PRIME appeared more effective in improving emotion recognition and global cognition than CG+PRIME. Future analyses will test the relationship between hours of cognitive training completed; PRIME use; and changes in cognition, motivation, symptoms, and functioning.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02782442; https://clinicaltrials.gov/study/NCT02782442.

Working memory training for reward processing in university students with subsyndromal depression: The influence of baseline severity of depression

Previous studies have tentatively suggested that working memory training (WMT) has the potential to improve reward processing, but it is not known how long this improvement lasts, whether there is a lag effect, or whether it is reflected in neurophysiological indicators. In this study, 40 university students with subsyndromal depression were randomly assigned to a training group or a control group and completed a 20-day working memory training task and a simple memory task, respectively. All participants completed the Temporal Experience of Pleasure Scale (TEPS) and a doors task with electroencephalogram (EEG) signals recorded simultaneously on a pre- and post-test and a 3-month follow-up. The reward-related positivity (RewP) amplitude, theta power, and their differences between conditions (i.e., ΔRewP and Δtheta power, respectively) in the doors task were the primary outcomes, and the score on TEPS was the secondary outcome. The results indicated no group-related effects were demonstrated in primary and secondary outcomes at post-test and 3-month follow-up. Furthermore, the differences in the pre- and post-test in Δtheta power were moderated by the baseline severity of depression. This was primarily driven by the fact that the change values in the control group increased with the severity of depression, while the change values in the training group had high homogeneity. Our findings did not provide support for the effect of WMT on reward processing across the whole sample, but without intervention, there would be high heterogeneity in the change in the cognitive control ability to loss feedback, which is detrimental to individuals with high depression severity.

The role of defeatist performance beliefs on cognitive effort-cost decision-making in schizophrenia

Impairments in effort-cost decision-making have been consistently observed in people with schizophrenia (SZ) and may be an important mechanism of negative symptoms. However, the processes that give rise to impairments in effort-cost decision-making are unclear, leading to limited progress in identifying the most relevant treatment targets. Drawing from cognitive models of negative symptoms and goal-directed behavior, this study aimed to examine how and under what type of task conditions defeatist performance beliefs contribute to these decision-making processes. Outpatients with SZ (n = 30) and healthy controls (CN; n = 28) completed a cognitive effort allocation task, the Cognitive Effort-Discounting (COGED) task, which assesses participants' willingness to exert cognitive effort for monetary rewards based on parametrically varied working memory demands (completing N-back levels). Results showed that although participants with SZ demonstrated reduced willingness to work for rewards across N-back levels compared to CN participants, they showed less choice modulation across different N-back conditions. However, among SZ participants with greater defeatist performance beliefs, there was a reduced willingness to choose the high effort option at higher N-back levels (N-back levels 3, 4, and 5 versus 2-back). Results suggest that compared to CN, the SZ group's subjective willingness to expend effort largely did not dynamically adjust as cognitive load increased. However, defeatist beliefs may undermine willingness to expend cognitive effort, especially when cognitive task demands are high. These beliefs may be a viable treatment target to improve effort-cost decision-making impairments in people with SZ.

Revisiting reward impairments in schizophrenia spectrum disorders: a systematic review and meta-analysis for neuroimaging findings

BACKGROUND

Abnormal reward functioning is central to anhedonia and amotivation symptoms of schizophrenia (SCZ). Reward processing encompasses a series of psychological components. This systematic review and meta-analysis examined the brain dysfunction related to reward processing of individuals with SCZ spectrum disorders and risks, covering multiple reward components.

METHODS

After a systematic literature search, 37 neuroimaging studies were identified and divided into four groups based on their target psychology components (i.e. reward anticipation, reward consumption, reward learning, effort computation). Whole-brain Seed-based d Mapping (SDM) meta-analyses were conducted for all included studies and each component.

RESULTS

The meta-analysis for all reward-related studies revealed reduced functional activation across the SCZ spectrum in the striatum, orbital frontal cortex, cingulate cortex, and cerebellar areas. Meanwhile, distinct abnormal patterns were found for reward anticipation (decreased activation of the cingulate cortex and striatum), reward consumption (decreased activation of cerebellum IV/V areas, insula and inferior frontal gyri), and reward learning processing (decreased activation of the striatum, thalamus, cerebellar Crus I, cingulate cortex, orbitofrontal cortex, and parietal and occipital areas). Lastly, our qualitative review suggested that decreased activation of the ventral striatum and anterior cingulate cortex was also involved in effort computation.

CONCLUSIONS

These results provide deep insights on the component-based neuro-psychopathological mechanisms for anhedonia and amotivation symptoms of the SCZ spectrum.

Altered brain functional networks in schizophrenia with persistent negative symptoms: an activation likelihood estimation meta-analysis

Objective

To investigate brain structural and functional characteristics of three brain functional networks including default mode network (DMN), central executive network (CEN), and salience network (SN) in persistent negative symptoms (PNS) patients.

Methods

We performed an activation likelihood estimation (ALE) meta-analysis of functional connectivity (FC) studies and voxel-based morphometry (VBM) studies to detect specific structural and functional alterations of brain networks between PNS patients and healthy controls.

Results

Seventeen VBM studies and twenty FC studies were included. In the DMN, PNS patients showed decreased gray matter in the bilateral medial frontal gyrus and left anterior cingulate gyrus and a significant reduction of FC in the right precuneus. Also, PNS patients had a decrease of gray matter in the left inferior parietal lobules and medial frontal gyrus, and a significant reduction of FC in the bilateral superior frontal gyrus in the CEN. In comparison with healthy controls, PNS patients exhibited reduced gray matter in the bilateral insula, anterior cingulate gyrus, left precentral gyrus and right claustrum and lower FC in these brain areas in the SN, including the left insula, claustrum, inferior frontal gyrus and extra-nuclear.

Conclusion

This meta-analysis reveals brain structural and functional imaging alterations in the three networks and the interaction among these networks in PNS patients, which provides neuroscientific evidence for more personalized treatment.Systematic Review RegistrationThe PROSPERO (https://www.crd.york.ac.uk/PROSPERO/, registration number: CRD42022335962).

Effort-related effects of chronic administration of the DA D2 receptor antagonist haloperidol via subcutaneous programmable minipumps: Reversal by co-administration of the adenosine A2A antagonist istradefylline

RATIONALE

Long-acting antipsychotics such as haloperidol decanoate are becoming more commonly used. Long-acting depot formulations have several advantages, but secondary negative effects of prolonged delivery, including motivational dysfunctions, could have debilitating effects. Assessing the behavioral changes that emerge during chronic antipsychotic administration in rats could provide insight regarding the development of motivational dysfunctions and drug tolerance.

OBJECTIVES

Acute administration of dopamine D2 antagonists such as haloperidol induce motivational deficits in rats, as marked by a shift towards a low-effort bias during effort-based choice tasks. In the present studies, programmable subcutaneous infusion pumps provided continuous and controlled drug delivery of haloperidol. Animals were assessed using a fixed ratio (FR) 5 lever pressing schedule and the FR5/chow feeding test of effort-based choice. The adenosine A2A antagonist istradefylline was studied for its ability to reverse the effects of chronic haloperidol.

RESULTS

Continuous chronic infusions of haloperidol produced significant reductions in FR5 performance and a shift from lever pressing to chow intake in rats tested on FR5/chow feeding choice, with no evidence of tolerance over the 4-week infusion period. Behavior returned to baseline during the vehicle-infusion washout period. Istradefylline significantly reversed the effects of haloperidol, increasing lever pressing and decreasing chow intake in haloperidol-treated rats.

CONCLUSIONS

These studies provide an important behavioral characterization of the effects of chronically infused haloperidol, and demonstrate that A2A antagonism reverses the effects of chronic haloperidol. This research could contribute to the understanding and treatment of motivational dysfunctions seen in schizophrenia, Parkinson's disease, and other disorders involving dopamine.

The prediction of effort-reward imbalance for reward motivation

This sequential mediation analysis study examined how the baseline effort-reward imbalance (ERI) would predict reward motivation 1 year later in 435 college students. We found that negative/disorganized schizotypal traits and anticipatory pleasure experience together mediate the prediction of ERI for reward motivation.

Anhedonia and impulsivity in college alcohol use: A path analysis

OBJECTIVE

Alcohol use is a substantial problem among college students and has several negative consequences. The current study examined the associations between anhedonia and alcohol use and related problems via impulsive behavior (e.g., negative urgency, sensation seeking). We parsed anhedonia into four specific facets: consummatory, anticipatory, recreational, and social anhedonia.

PARTICIPANTS

Six hundred and forty college students aged 18-25 were included in the final analysis.

METHOD

Data were collected via Amazon Mechanical Turk. Self-report inventories assessing for anhedonia, alcohol use, impulsive behavior, and depressed mood were utilized.

RESULTS

Recreational consummatory anhedonia was negatively associated with alcohol use and alcohol-related problems through negative urgency. Recreational consummatory anhedonia also had significant negative associations with alcohol consumption via sensation seeking. Further, social anticipatory anhedonia was positively associated with alcohol use and related problems via negative urgency.

CONCLUSIONS

This study highlights important associations between anhedonia, impulsivity, and alcohol use and related problems.

Negative symptoms and sex differences in first episode schizophrenia: What's their role in the functional outcome? A longitudinal study

INTRODUCTION

Negative symptoms (NS) include asociality, avolition, anhedonia, alogia, and blunted affect and are linked to poor prognosis. It has been suggested that they reflect two different factors: diminished expression (EXP) (blunted affect and alogia) and amotivation/pleasure (MAP) (anhedonia, avolition, asociality). The aim of this article was to examine potential sex differences among first-episode schizophrenia (FES) patients and analyze sex-related predictors of two NS symptoms factors (EXP and MAP) and functional outcome.

MATERIAL AND METHODS

Two hundred and twenty-three FES (71 females and 152 males) were included and evaluated at baseline, six-months and one-year. Repeated measures ANOVA was used to examine the effects of time and sex on NS and a multiple linear regression backward elimination was performed to predict NS factors (MAP-EXP) and functioning.

RESULTS

Females showed fewer NS (p=0.031; Cohen's d=-0.312), especially those related to EXP (p=0.024; Cohen's d=-0.326) rather than MAP (p=0.086), than males. In both male and female group, worse premorbid adjustment and higher depressive symptoms made a significant contribution to the presence of higher deficits in EXP at one-year follow-up, while positive and depressive symptoms predicted alterations in MAP. Finally, in females, lower deficits in MAP and better premorbid adjustment predicted better functioning at one-year follow-up (R2=0.494; p<0.001), while only higher deficits in MAP predicted worse functioning in males (R2=0.088; p=0.012).

CONCLUSIONS

Slightly sex differences have been found in this study. Our results lead us to consider that early interventions of NS, especially those focusing on motivation and pleasure symptoms, could improve functional outcomes.

The structure stability of negative symptoms: longitudinal network analysis of the Brief Negative Symptom Scale in people with schizophrenia

BACKGROUND

The structure of negative symptoms of schizophrenia is still a matter of controversy. Although a two-dimensional model (comprising the expressive deficit dimension and the motivation and pleasure dimension) has gained a large consensus, it has been questioned by recent investigations.

AIMS

To investigate the latent structure of negative symptoms and its stability over time in people with schizophrenia using network analysis.

METHOD

Negative symptoms were assessed in 612 people with schizophrenia using the Brief Negative Symptom Scale (BNSS) at baseline and at 4-year follow-up. A network invariance analysis was conducted to investigate changes in the network structure and strength of connections between the two time points.

RESULTS

The network analysis carried out at baseline and follow-up, supported by community detection analysis, indicated that the BNSS's items aggregate to form four or five distinct domains (avolition/asociality, anhedonia, blunted affect and alogia). The network invariance test indicated that the network structure remained unchanged over time (network invariance test score 0.13; P = 0.169), although its overall strength decreased (6.28 at baseline, 5.79 at follow-up; global strength invariance test score 0.48; P = 0.016).

CONCLUSIONS

The results lend support to a four- or five-factor model of negative symptoms and indicate overall stability over time. These data have implications for the study of pathophysiological mechanisms and the development of targeted treatments for negative symptoms.

Social Motivation in Schizophrenia: What's Effort Got to Do With It?

BACKGROUND AND HYPOTHESIS

Social motivation, defined as the fundamental human desire to seek out, engage in, and maintain interpersonal bonds, has become a growing area of research in schizophrenia. The major focus has been on understanding the impact of social reward-related processes. An obvious but rarely acknowledged fact is that social interactions, much like other goal-directed acts, require the exertion of effort. In this Review Article, we argue that social motivation in schizophrenia can be conceptualized through the lens of an established framework: effort-based decision-making (EBDM).

STUDY DESIGN

We conducted a literature review on social reward processing in schizophrenia, then extended these findings by applying concepts and insights from the literature on EBDM to the study of social motivation.

STUDY RESULTS

Within the EBDM framework, decisions about whether or not to pursue social interactions are bound by cost/benefit calculations. That is, people do not pursue social behaviors when the estimated "cost" of the required effort outweighs the anticipated "benefit" or reward. We propose that people with schizophrenia are less likely to engage in social interaction compared with healthy samples because they: (1) underestimate the benefits of relationships (based on expectations of reward/punishment), (2) overestimate the effort costs associated with social interaction, and/or (3) fail to integrate cost-benefit information in an optimal manner.

CONCLUSIONS

EBDM is an especially promising framework of social motivation that goes beyond the current focus on social reward processing to include a focus on effort.

Functional connectivity in a monetary and social incentive delay task in medicated patients with schizophrenia

Introduction

Numerous studies indicate impaired reward-related learning in individuals with schizophrenia, with various factors such as illness duration, medication, disease severity, and level of analysis (behavioral or neurophysiological data) potentially confounding the results. Patients with schizophrenia who are treated with second-generation antipsychotics have been found to have a less affected reward system. However, this finding does not explain the neural dysfunctions observed in previous studies. This study aimed to address the open question of whether the less impaired reward-related behavior is associated with unimpaired task-related functional connectivity or altered task-related functional connectivity.

Methods

The study included 23 participants diagnosed within the schizophrenia spectrum and 23 control participants matched in terms of age, sex, and education. Participants underwent an MRI while performing a monetary incentive delay task and a social incentive delay task. The collected data were analyzed in terms of behavior and functional connectivity.

Results

Both groups exhibited a main effect of reward type on behavioral performance, indicating faster reaction times in the social incentive delay task, but no main effect of reward level. Altered functional connectivity was observed in predictable brain regions within the patient group, depending on the chosen paradigm, but not when compared to healthy individuals.

Discussion

In addition to expected slower response times, patients with schizophrenia demonstrated similar response patterns to control participants at the behavioral level. The similarities in behavioral data may underlie different connectivity patterns. Our findings suggest that perturbations in reward processing do not necessarily imply disturbances in underlying connectivities. Consequently, we were able to demonstrate that patients with schizophrenia are indeed capable of exhibiting goal-directed, reward-responsive behavior, although there are differences depending on the type of reward.

Prospection deficits in patients with first-episode schizophrenia: a cross-sectional comparative study

Prospection refers to the ability to simulate and pre-experience future events. Schizophrenia patients have difficulty in anticipating pleasure in future events, but previous studies examined prospection deficits in chronic schizophrenia patients. This study aimed to investigate prospection deficits in first-episode schizophrenia patients. Thirty first-episode schizophrenia patients and 31 healthy controls completed the Affective Prospection Task, which utilized pictorial cues to involve positive, neutral and negative prospection. Participants' ratings regarding the phenomenal characteristics of their prospected events were collected, and their prospected narratives were coded using a valid scoring manual. We also assessed intelligence, working memory and logical memory. The results showed, in all participants, valence of the cues significantly influenced participants' sense of pre-experience, temporal distance, emotion experience, vividness and participation of the prospected events, as well as the richness of sensory details. The two groups did not differ in self-report phenomenal characteristics of their prospected events. For coded characteristics, schizophrenia patients' prospected narratives were less rich in thought/emotion than controls, even after controlling for intelligence and memory deficits. We extended empirical evidence for prospection deficits from chronic schizophrenia samples to first-episode schizophrenia patients.

"Goals in Focus"-a targeted CBT approach for motivational negative symptoms of psychosis: study protocol for a randomized-controlled feasibility trial

BACKGROUND

The reduction of goal-directed behavior is the main characteristic in motivational negative symptoms of psychosis as it accounts for the long-term decline in psychological well-being and psychosocial functioning. However, the available treatment options are largely unspecific and show only small effects on motivational negative symptoms. Interventions that directly target the relevant psychological mechanisms are likely to be more effective. For "Goals in Focus", we translated findings from basic clinical research on mechanisms underlying motivational negative symptoms into a tailored and comprehensive novel psychological outpatient treatment program. With this study, we will test the feasibility of the therapy manual and the trial procedures. We also aim to examine first estimates of the effect size that can be expected from "Goals in Focus" to inform the sample size calculation of a subsequent fully powered trial.

METHODS

Thirty participants diagnosed with a schizophrenia spectrum disorder and at least moderate motivational negative symptoms will be randomly assigned to either 24 sessions of "Goals in Focus" over the course of 6 months (n = 15) or to a 6-month wait-list control group (n = 15). Single-blind assessments will be conducted at baseline (t₀) and 6 months after baseline completion (t₁). Feasibility outcomes include patient recruitment, retention, and attendance rates. Acceptability will be rated by trial therapists and by participants at end of treatment. Primary outcome for effect size estimation is the motivational negative symptom subscale sum score of the Brief Negative Symptom Scale at t₁ corrected for baseline values. Secondary outcomes include psychosocial functioning, psychological well-being, depressive symptoms, expressive negative symptoms, negative symptom factor scores, and goal pursuit in everyday life.

DISCUSSION

The feasibility and acceptability data will be used to improve trial procedures and the "Goals in Focus" intervention where necessary. The treatment effect on the primary outcome will provide the basis for the sample size calculation for a fully powered RCT.

TRIAL REGISTRATION

1) ClinicalTrials.gov, NCT05252039 . Registered on 23 February 2022. 2) Deutsches Register Klinischer Studien, DRKS00018083 . Registered on 28 August 2019.

The motivation and pleasure deficits but not expressivity affects social functioning through cognitive function in male patients with schizophrenia: A structural equation model

OBJECTIVE

This study aims to compare cognitive function and social functioning in male schizophrenia patients with deficit syndrome (DS) and non-DS, and to explore the associations among two different dimensions of negative symptoms (motivation and pleasure (MAP) and expressivity (EXP) deficits), cognitive function and social functioning base on a Structural Equation Model (SEM).

METHODS

The current study enrolled 161 male schizophrenia patients and 120 age- and education- matched healthy controls. The DS and non-DS group were categorized by the Chinese version of Schedule for the Deficit Syndrome (SDS). The psychotic and negative symptoms were evaluated by the Brief Psychiatric Rating Scale (BPRS) and the Brief Negative Symptoms Scale (BNSS). The Social functioning was measured by Scale of Social function in Psychosis Inpatients (SSPI). A battery of classical neurocognitive tests was used for assessing cognition including sustained vigilance/attention, cognitive flexibility, ideation fluency and visuospatial memory.

RESULTS

Our study indicated that DS patients performed worser in cognitive function and social functioning than non-DS patients. The SEM model demonstrated that MAP significantly affected social functioning through direct influence and mediation of cognitive function. However, our results found that EXP had little influence on cognitive function and social function.

CONCLUSION

Our findings provided evidence supporting that DS may represent as a subtype of schizophrenia, and the MAP factor play a pivotal role to influence the cognitive and social functioning in schizophrenia patients.

Effort-cost decision-making in psychotic and mood disorders

Avolition and anhedonia are core symptoms across psychosis and mood disorders. One important mechanism thought to relate to these symptoms is effort-cost decision-making (ECDM), the valuation and estimation of work required to obtain a given reward. While recent work suggests impairments in ECDM in both mood disorders and psychosis relative to controls, limited work has taken a transdiagnostic approach to examine how these deficits relate to different symptom profiles across disorders. The present study investigated ECDM across schizophrenia/schizoaffective disorder (N = 33), bipolar disorder (N = 47), unipolar depression (N = 61), and healthy controls (N = 58) to examine willingness to expend physical effort. Moreover, we examined the relationship between ECDM and motivation and pleasure symptoms across participants. We found that people with schizophrenia and bipolar disorder showed a reduced willingness to expend physical effort at high reward values relative to controls, while as a group, those with depression showed no differences relative to controls. However, individual differences in self-reported motivation and pleasure predicted reduced ECDM, particularly at high reward values, suggesting that both severity of symptoms and diagnostic categories are important for understanding altered ECDM in psychopathology. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A highly replicable decline in mood during rest and simple tasks

Does our mood change as time passes? This question is central to behavioural and affective science, yet it remains largely unexamined. To investigate, we intermixed subjective momentary mood ratings into repetitive psychology paradigms. Here we demonstrate that task and rest periods lowered participants' mood, an effect we call 'Mood Drift Over Time'. This finding was replicated in 19 cohorts totalling 28,482 adult and adolescent participants. The drift was relatively large (-13.8% after 7.3 min of rest, Cohen's d = 0.574) and was consistent across cohorts. Behaviour was also impacted: participants were less likely to gamble in a task that followed a rest period. Importantly, the drift slope was inversely related to reward sensitivity. We show that accounting for time using a linear term significantly improves the fit of a computational model of mood. Our work provides conceptual and methodological reasons for researchers to account for time's effects when studying mood and behaviour.

Bridge centrality network structure of negative symptoms in people with schizophrenia

Negative symptoms are complex psychopathology. Although evidence generally supported the NIMH five consensus domains, research seldom examined measurement invariance of this model, and domain-specific correspondence across multiple scales. This study aimed to examine the interrelationship between negative symptom domains captured by different rating scales, and to examine the domain-specific correspondence across multiple scales. We administered the Brief Negative Symptom Scale (BNSS), the Self-evaluation of Negative Symptoms (SNS), and the Scale for Assessment of Negative Symptoms (SANS) to 204 individuals with schizophrenia. We used network analysis to examine the interrelationship between negative symptom domains. Besides regularized partial correlation network, we estimated bridge centrality indices to investigate domain-specific correspondence, while taking each scale as an independent community. The regularized partial correlation network showed that the SNS nodes clustered together, whereas the SANS and the BNSS nodes intermingled together. The SANS attention domain lied at the periphery of the network according to the Fruchterman-Reingold algorithm. The SANS anhedonia-asociality (strength = 1.48; EI = 1.48) and the SANS affective flattening (strength = 1.06; EI = 1.06) had the highest node strength and EI. Moreover, the five nodes of the BNSS bridged the nodes of the SANS and the SNS. BNSS blunted affect (strength = 0.76; EI = 0.76) and SANS anhedonia-asociality (strength = 0.76; EI = 0.74) showed the highest bridge strength and bridge EI. The BNSS captures negative symptoms and bridges the symptom domains measured by the SANS and the SNS. The three scales showed domain-specific correspondence.

Anhedonia and suicidal ideation in young people with early psychosis: Further findings from the 2-year follow-up of the ReARMS program

Hedonic deficits have been extensively studied in schizophrenia, but little is known about their association with suicidal ideation in early psychosis. The aim of this research was to examine the relationship between anhedonia and suicidal thoughts across a 2-year follow-up period in people with First Episode Psychosis (FEP) and at Ultra High Risk (UHR) of psychosis. Ninty-six UHR and 146 FEP, aged 13-35 years, completed the Comprehensive Assessment of At-Risk Mental States (CAARMS) and the Beck Depression Inventory-II (BDI-II). The BDI-II "Anhedonia" subscale score to assess anhedonia and the CAARMS "Depression" item 7.2 subscore to measure depression were used across the 2 years of follow-up. Hierarchical regression analyses were performed. No difference in anhedonia scores between FEP and UHR individuals was found. In the FEP group, a significant enduring association between anhedonia and suicidal ideation was found at baseline and across the follow-up, independent of clinical depression. In the UHR subgroup, the enduring relationship between anhedonia and suicidal thoughts were not completely independent from depression severity. Anhedonia is relevant in predicting suicidal ideation in early psychosis. Specific pharmacological and/or psychosocial interventions on anhedonia within specialized EIP program could reduce suicide risk overtime.

Emotion-behaviour decoupling and experiential pleasure deficits predict negative symptoms and functional outcome in first-episode schizophrenia patients

BACKGROUND

Emotion-behaviour decoupling refers to the failure to translate emotion into motivated behaviour, and is a putative marker for schizophrenia. The heterogeneity of experiential pleasure and emotion expressivity deficits has been reported in schizophrenia patients. These three constructs are believed to contribute to negative symptoms, but very few studies have examined their predictive ability for clinical and functional outcome of schizophrenia. This study aimed to clarify whether these three constructs influence clinical and functional outcome of schizophrenia.

METHOD

At baseline, 127 first-episode schizophrenia patients completed a behavioural paradigm for emotion-behaviour decoupling, and self-report scales for experiential pleasure and emotion expressivity deficits. Cluster-analysis was applied to characterize schizophrenia subgroups based on these three constructs. At end-point (mean follow-up = 5.37 years, SD = 1.03 years), 85 schizophrenia patients were reassessed using the Clinical Assessment Interview for Negative Symptoms (CAINS) and a clinician-rated social functioning scale.

RESULTS

Cluster 1 (n = 74) did not show emotion-behaviour decoupling, and had intact experiential pleasure and emotion expressivity. Cluster 2 (n = 29) showed emotion-behaviour decoupling and experiential pleasure deficits. Cluster 3 (n = 24) showed emotion expressivity deficits. At endpoint, the three clusters differed significantly in CAINS MAP factor (p = 0.016) and social functioning (p = 0.019), but not CAINS EXP factor. Specifically, Cluster 2 (n = 18) showed more severe negative symptoms of CAINS MAP factor (p = 0.046) and poorer social functioning (p = 0.022) than Cluster 1 (n = 49). Cluster 3 (n = 18) did not differ from Cluster 1 and Cluster 2 in negative symptoms and social functioning.

DISCUSSION

Emotion-behaviour decoupling and experiential pleasure deficits predicted clinical and functional outcome of schizophrenia.

A computational neuroimaging study of reinforcement learning and goal-directed exploration in schizophrenia spectrum disorders

BACKGROUND

Prior evidence indicates that negative symptom severity and cognitive deficits, in people with schizophrenia (PSZ), relate to measures of reward-seeking and loss-avoidance behavior (implicating the ventral striatum/VS), as well as uncertainty-driven exploration (reliant on rostrolateral prefrontal cortex/rlPFC). While neural correlates of reward-seeking and loss-avoidance have been examined in PSZ, neural correlates of uncertainty-driven exploration have not. Understanding neural correlates of uncertainty-driven exploration is an important next step that could reveal insights to how this mechanism of cognitive and negative symptoms manifest at a neural level.

METHODS

We acquired fMRI data from 29 PSZ and 36 controls performing the Temporal Utility Integration decision-making task. Computational analyses estimated parameters corresponding to learning rates for both positive and negative reward prediction errors (RPEs) and the degree to which participates relied on representations of relative uncertainty. Trial-wise estimates of expected value, certainty, and RPEs were generated to model fMRI data.

RESULTS

Behaviorally, PSZ demonstrated reduced reward-seeking behavior compared to controls, and negative symptoms were positively correlated with loss-avoidance behavior. This finding of a bias toward loss avoidance learning in PSZ is consistent with previous work. Surprisingly, neither behavioral measures of exploration nor neural correlates of uncertainty in the rlPFC differed significantly between groups. However, we showed that trial-wise estimates of relative uncertainty in the rlPFC distinguished participants who engaged in exploratory behavior from those who did not. rlPFC activation was positively associated with intellectual function.

CONCLUSIONS

These results further elucidate the nature of reinforcement learning and decision-making in PSZ and healthy volunteers.

The positivity offset theory of anhedonia in schizophrenia: evidence for a deficit in daily life using digital phenotyping

BACKGROUND

Negative symptoms of schizophrenia have recently been proposed to result from a decoupling of (intact) hedonic experience and (diminished) approach behavior. The current study challenged this view by exploring the hypothesis that negative symptoms are driven by a specific type of emotional experience abnormality, a reduction in the positivity offset (i.e. the tendency to experience greater levels of positive relative to negative emotion in low-arousal contexts), which limits the production of approach behaviors in neutral environments.

METHODS

Participants included outpatients with SZ (n = 44) and healthy controls (CN: n = 48) who completed one week of active (ecological momentary assessment surveys of emotional experience and symptoms) and passive (geolocation, accelerometry) digital phenotyping. Mathematical modeling approaches from Cacioppo's Evaluative Space Model were used to quantify the positivity offset in daily life. Negative symptoms were assessed via standard clinical ratings, as well as active (EMA surveys) and passive (geolocation, accelerometry) digital phenotyping measures.

RESULTS

Results indicated that the positivity offset was reduced in SZ and associated with more severe anhedonia and avolition measured via clinical interviews and active and passive digital phenotyping.

CONCLUSIONS

These findings suggest that current conceptual models of negative symptoms, which assume hedonic normality, may need to be revised to account for reductions in the positivity offset and its connection to diminished motivated behavior. Findings identify key real-world contexts where negative symptoms could be targeted using psychosocial treatments.

Reduced willingness to expend effort for rewards is associated with risk for conversion and negative symptom severity in youth at clinical high-risk for psychosis

BACKGROUND

Schizophrenia (SZ) is typically preceded by a prodromal (i.e. pre-illness) period characterized by attenuated positive symptoms and declining functional outcome. Negative symptoms are prominent among individuals at clinical high-risk (CHR) for psychosis (i.e. those with prodromal syndromes) and predictive of conversion to illness. Mechanisms underlying negative symptoms are unclear in the CHR population.

METHODS

The current study evaluated whether CHR participants demonstrated deficits in the willingness to expend effort for rewards and whether these impairments are associated with negative symptoms and greater risk for conversion. Participants included 44 CHR participants and 32 healthy controls (CN) who completed the Effort Expenditure for Reward Task (EEfRT).

RESULTS

Compared to CN, CHR participants displayed reduced likelihood of exerting high effort for high probability and magnitude rewards. Among CHR participants, reduced effort expenditure was associated with greater negative symptom severity and greater probability of conversion to a psychotic disorder on a cross-sectional risk calculator.

CONCLUSIONS

Findings suggest that effort-cost computation is a marker of illness liability and a transphasic mechanism underlying negative symptoms in the SZ spectrum.

The therapeutic role of ketamine and esketamine in treating psychopathological domains of depression

Over the past two decades, ketamine has emerged as a novel effective and rapid-acting antidepressant. While the vast majority of studies on ketamine have focused on its ability to reduce the severity of depression broadly, its effectiveness in specific domains such as cognition, anhedonia, suicidality, and workplace/social/scholastic functionality has been neglected. Similarly, current treatments (e.g., SSRIs and SNRIs) aim to improve overall depression severity, which often results in the persistence of one or more residual symptom domains and prevents full recovery to premorbid functionality. In this review, we narratively synthesize the literature pertaining to the effectiveness of ketamine in treating key domains of depressive symptomatology (i.e., cognition, anhedonia, suicidality, and psychosocial functionality). Our findings suggest that ketamine is effective across domains varyingly, with the strongest evidence being for its ability to reduce suicidality. The rapid acting nature of ketamine further supports its use in treating suicidality and potentially preventing the completion of suicide. Evidence for the effectiveness of ketamine in other domains is weak, primarily due to a lack of robust studies specifically designed to assess these domains as primary outcomes. Future studies should scrutinize the effects of ketamine on specific domains of depression to optimize its implementation.

Remote Assessment of Negative Symptoms of Schizophrenia

In contrast to the validated scales for face-to-face assessment of negative symptoms, no widely accepted tools currently exist for remote monitoring of negative symptoms. Remote assessment of negative symptoms can be broadly divided into 3 categories: (1) remote administration of an existing negative-symptom scale by a clinician, in real time, using videoconference technology to communicate with the patient; (2) direct inference of negative symptoms through detection and analysis of the patient's voice, appearance, or activity by way of the patient's smartphone or other device; and (3) ecological momentary assessment, in which the patient self-reports their condition upon receipt of periodic prompts from a smartphone or other device during their daily routine. These modalities vary in cost, technological complexity, and applicability to the different negative-symptom domains. Each modality has unique strengths, weaknesses, and issues with validation. As a result, an optimal solution may be more likely to employ several techniques than to use a single tool. For remote assessment of negative symptoms to be adopted as primary or secondary endpoints in regulated clinical trials, appropriate psychometric standards will need to be met. Standards for substituting 1 set of measures for another, as well as what constitutes a "gold" reference standard, will need to be precisely defined and a process for defining them developed. Despite over 4 decades of progress toward this goal, significant work remains to be done before clinical trials addressing negative symptoms can utilize remotely assessed secondary or primary outcome measures.

Transforming experiences: Neurobiology of memory updating/editing

Long-term memory is achieved through a consolidation process where structural and molecular changes integrate information into a stable memory. However, environmental conditions constantly change, and organisms must adapt their behavior by updating their memories, providing dynamic flexibility for adaptive responses. Consequently, novel stimulation/experiences can be integrated during memory retrieval; where consolidated memories are updated by a dynamic process after the appearance of a prediction error or by the exposure to new information, generating edited memories. This review will discuss the neurobiological systems involved in memory updating including recognition memory and emotional memories. In this regard, we will review the salient and emotional experiences that promote the gradual shifting from displeasure to pleasure (or vice versa), leading to hedonic or aversive responses, throughout memory updating. Finally, we will discuss evidence regarding memory updating and its potential clinical implication in drug addiction, phobias, and post-traumatic stress disorder.