Anhedonia and depression symptoms have been linked to potential deficits in reward learning. However, how anhedonia impacts the ability to adjust and learn about the effort required to obtain rewards remains unclear.

We examined young people (N = 155, 16–25 years) with a range of depression and anhedonia symptoms using a probabilistic instrumental reward and effort learning task. Participants were asked to learn which options to choose to maximize reward or minimize effort for reward. We compared the exerted effort (button pressing speed) for high (puppy images) vs low (dog images) rewards and collected subjective reports of “liking,” “wanting,” and “willingness to exert effort.” Computational models were fit to the learning data and estimated parameter values were correlated with depression and anhedonia symptoms.

As depression symptoms and consummatory anhedonia increased, reward liking decreased, and as anticipatory anhedonia increased, liking, wanting, and willingness to exert effort for reward decreased.

Participants exerted more effort for high rewards than for low rewards, but anticipatory anhedonia diminished this difference.

Higher consummatory anhedonia was associated with poorer reward and effort learning, and with increased temperature parameter values for both learning types, indicating a higher tendency to make exploratory choices. Higher depression symptoms were associated with lower reward learning accuracy.

We provide novel evidence that anhedonia is associated with difficulties in modulating effort as a function of reward value and with the underexploitation of low effort and high reward options. We suggest that addressing these impairments could be a novel target for intervention in anhedonic young people.

Conduct disorder and childhood head injuries frequently co-occur and are linked to a higher risk of later delinquency. While both are known to disrupt reward-related neural circuits, this study investigated whether their combined presence leads to a unique disruption in these pathways, potentially accounting for the increased risk of delinquency.

Using neuroimaging data from the baseline (age 9–10) assessment from the Adolescent Brain and Cognitive Development (ABCD) study, four groups were compared: children with conduct disorder (CD, n = 588), a mild traumatic brain injury (mTBI, n = 1,216), both (mTBI+CD, n = 252), and typically developing controls (TD, n = 705). Neural activation in eight regions of interest (amygdala, hippocampus, nucleus accumbens, caudal anterior cingulate cortex, rostral anterior cingulate cortex, medial orbitofrontal cortex, thalamus, and insula) during reward anticipation and receipt were assessed during the monetary incentive delay task.

After controlling for several covariates, including sex, ADHD, and internalizing problems, the mTBI+CD group displayed greater left amygdala and hippocampal activation during reward receipt compared to all other groups. While they displayed increased activation in the right hippocampus and thalamus compared to TD controls and the right hippocampus compared to the mTBI group, they did not differ from the CD group. No group differences emerged during reward anticipation.

Increased left amygdala and hippocampus activation in children with conduct disorder and a history of mild traumatic brain injury may reflect robust encoding of emotionally charged reward experiences, potentially reinforcing memory-guided, reward-seeking behaviors.

Weight suppression represents the difference between highest and current body weight and predicts maintenance of bulimia nervosa and related syndromes (BN-S). This study tested a biobehavioral model of binge-eating severity in which greater weight suppression links to reduced leptin, which links to reduced glucagon-like peptide 1 (GLP-1) release, which links to both decreased reward satiation and increased reward valuation, which link, respectively, to excessive food intake and loss of control while eating – the defining features of DSM-5 binge-eating episodes.

Women (N = 399) who met DSM-5 criteria for bulimia nervosa or another eating disorder with binge eating (n = 321) or had no lifetime eating disorder symptoms (n = 78) participated in a multi-visit protocol, including structured clinical interviews, height, weight, weight history, percent body fat, fasting leptin, post-prandial GLP-1 response to a fixed meal, and self-report and behavioral assessments of food reward satiation (ad lib meal) and food and nonfood reward valuation (progressive ratio tasks).

A structural equation model (SEM) demonstrated excellent fit to data with significant pathways from greater weight suppression to lower leptin, to blunted GLP-1 response, to lower reward satiation, to larger eating/binge-eating episode size, with significant indirect paths through leptin, GLP-1, and reward satiation. SEM with paths via reward valuation to loss of control eating demonstrated inadequate fit.

Findings specifically link reduced GLP-1 response to severity of binge-episode size and support weight history assessment in eating disorders, DSM-5 over ICD-11 criteria for binge eating, and may inform future clinical trials of GLP-1 agonists for BN-S.

Objective. Witnessing existential suffering in patients is associated with increased risks of compassion fatigue and burnout in palliative care physicians. Finding meaning is a protective factor for burnout and is associated with increased job satisfaction and a sense of purpose.

While the significance of finding meaning through the doctor-patient relationship is widely recognized, less is known about the subjective experience of palliative care physicians, how they ascribe meaning, and how meaning sustains them. The aim of this study was to describe and interpret how palliative care physicians experience meaning when caring for patients.

Method. Hermeneutic-phenomenology, inspired by the philosophy of Heidegger and Gadamer, informed the methodological approach. Ten palliative care physicians, caring for adult patients, completed semi-structured interviews. Van Manen’s “lifeworld existentials” supported our reflexive hermeneutic analysis to interpret participants’ moments of meaning-making.

Results. Our analysis identified two interpretive concepts for meaning-making: moments of connection and moments of transformation. Meaningful connection occurred when physicians and patients together acknowledged existential suffering in death and dying and experienced it on a personal, human level. Often, experiences were fleeting but had a lasting impact. Experiences of connection had a transformational effect on physicians and were associated with a sense of reward and purpose in palliative care work.

Significance of results. Findings are discussed in relation to philosophical literature on the experience of time, contrasting man-made time with the existential experience of time. Moments of connection and transformation experienced by palliative care physicians fueled their commitment to their profession. At a time when burn-out is rife, identifying, describing, and understanding moments of meaning may offer protective benefits for physicians working in palliative care.

To examine opinions about incentives for vaccination against COVID-19.

A qualitative study was conducted in spring 2022. The study population consisted of pairs of university students and their parents throughout Serbia. The qualitative content analysis was applied.

A total of 18 participants (9 student-parent pairs) were included. The following themes were identified: 1) Attitudes about financial incentives for vaccination, 2) Non-financial incentives for vaccination, and 3) Suggestions to enhance vaccination coverage. Theme 1 comprised several subthemes: General response to money, Dissatisfaction with financial incentives, Satisfaction with financial incentives and Amount of money to change people’s opinion. Most parents and some students expressed a clear dissatisfaction and disapproval of the concept of financial incentives for compliance with vaccination. Financial offers would not make our participants change their position on whether to receive the vaccine, as no major differences in attitude towards vaccinations between the vaccinated and the non-vaccinated study participants was observed. Non-financial incentives were more acceptable compared to financial ones, but they were also seen as beneficial for some and not others.

Financial incentive programs’ potential for inefficiency and public mistrust make other methods to boost vaccine uptake better public health choices for now.

According to the aberrant salience proposal, reward processing abnormality, specifically erroneous reward prediction error (RPE) signaling due to stimulus-independent release of dopamine, underlies delusions in schizophrenia. However, no studies to date have examined RPE-associated brain activations in relation to this symptom.

Seventy-eight patients with a DSM-5 diagnosis of schizophrenia/schizoaffective disorder and 43 healthy individuals underwent fMRI while they performed a probabilistic monetary reward task designed to generate a measure of RPE. Ratings of delusions and referentiality were made in the patients.

Using whole-brain, voxel-based analysis, schizophrenia patients showed only minor differences in RPE-associated activation compared to healthy controls. Within the patient group, however, severity of delusions was inversely associated with RPE-associated activation in areas including the caudate nucleus, the thalamus and the left pallidum, as well as the lateral frontal cortex bilaterally, the pre- and postcentral gyrus and supplementary motor area, the middle cingulate gyrus, and parts of the temporal and parietal cortex. A broadly similar pattern of association was seen for referentiality.

According to this study, while patients with schizophrenia as a group do not show marked alterations in RPE signaling, delusions and referentiality are associated with reduced activation in parts of the prefrontal cortex and the basal ganglia, though not specifically the ventral striatum. The direction of the changes is on the face of it contrary to that predicted by aberrant salience theory.

Negative symptoms are a key feature of several psychiatric disorders. Difficulty identifying common neurobiological mechanisms that cut across diagnostic boundaries might result from equifinality (i.e., multiple mechanistic pathways to the same clinical profile), both within and across disorders. This study used a data-driven approach to identify unique subgroups of participants with distinct reward processing profiles to determine which profiles predicted negative symptoms.

Participants were a transdiagnostic sample of youth from a multisite study of psychosis risk, including 110 individuals at clinical high-risk for psychosis (CHR; meeting psychosis-risk syndrome criteria), 88 help-seeking participants who failed to meet CHR criteria and/or who presented with other psychiatric diagnoses, and a reference group of 66 healthy controls. Participants completed clinical interviews and behavioral tasks assessing four reward processing constructs indexed by the RDoC Positive Valence Systems: hedonic reactivity, reinforcement learning, value representation, and effort–cost computation.

k-means cluster analysis of clinical participants identified three subgroups with distinct reward processing profiles, primarily characterized by: a value representation deficit (54%), a generalized reward processing deficit (17%), and a hedonic reactivity deficit (29%). Clusters did not differ in rates of clinical group membership or psychiatric diagnoses. Elevated negative symptoms were only present in the generalized deficit cluster, which also displayed greater functional impairment and higher psychosis conversion probability scores.

Contrary to the equifinality hypothesis, results suggested one global reward processing deficit pathway to negative symptoms independent of diagnostic classification. Assessment of reward processing profiles may have utility for individualized clinical prediction and treatment.

Ultrasonic vocalisations (USVs) emitted by rats may reflect affective states. Specifically, 50 kHz calls emitted during juvenile playing are associated with positive affect. Given that depression is characterised by profound alterations in this domain, we proposed that USV calls may configure a suitable tool for assessing depressive-like states. Utilising the Flinders Sensitive Line (FSL), a well-established animal model of depression, we assessed USV calls emitted by rats during tickling, a procedure based on juvenile rats’ rough-and-tumble play.

Juvenile FSL rats and their control counterparts, the Flinders Resistant Line (FRL) and Sprague Dawley, were submitted to tickling sessions to imitate rats playing behaviour. The rats were tickled daily for 6 weeks starting at PND21. Tickling sessions were recorded for further acoustic analysis of 50 kHz calls.

Tickling increased 50 kHz calls in all the strains. FSL rats emitted more calls than control strains and exhibited a higher number of flat-trill combination calls.

Tickling is a robust method for inducing 50 kHz USV calls. Analysing USV calls emitted during tickling configurates a suitable method for studying affective states relevant to depression. FSL rats did not present anhedonia but rather higher reward sensitivity, which may underlie their stress vulnerability.