Association of Cognitive Impairment With Anhedonia in Patients With Schizophrenia

Anhedonia is considered as one of the five dimensions of negative symptoms and mainly refers to the reduction of the capacity of feeling pleasure. Increasing evidence suggests that anhedonia in schizophrenia may be partly explained by cognitive impairment. However, the associations between specific cognitive impairment and anhedonia are not fully investigated. The purpose of this study was to examine anticipatory anhedonia, consummatory anhedonia, and their cognitive associations in schizophrenia. A total number of 100 patients with schizophrenia and 67 healthy volunteers were recruited. The clinical symptoms of schizophrenia were assessed. Anticipatory pleasure, consummatory pleasure, and cognitive functions of each participant were measured. Multiple linear regression analysis was performed to investigate the influencing factors of anhedonia in schizophrenia. The results showed no significant differences in sex, age, education year, body mass index (BMI), and marital status between the schizophrenia group and healthy control group (all P > 0.05). Both anticipatory and consummatory pleasure in the schizophrenia group were significantly lower than those in the healthy control group (all P < 0.05). Immediate memory, visual spanning, language, attention, and delayed memory were significantly poorer in the schizophrenia group (all P < 0.05). The results showed that language deficit is an independent risk factor for anticipatory anhedonia (B' = 0.265, P = 0.008, 95% CI: 0.038-0.244), while delayed memory deficit is an independent risk factor for consummatory anhedonia (B' = 0.391, P < 0.001, 95% CI:0.085-0.237). To the best of our knowledge, this is the first study that reported the specific cognitive associations of anhedonia in schizophrenia. The findings have added new evidence on the influencing factors of anhedonia and provided clues for the associations between clinical manifestations of schizophrenia.

Anhedonia sub-components and reward and effort learning for primary and secondary rewards in young people with depression symptoms

Background: Anhedonia, a central depression symptom, is associated with impairments in reward processing. However how the sub-components of reward processing (anticipation, motivation, consummation and learning) are related to depression symptoms is not well understood. In particular, little is known about how effort cost and reward learning is related to anhedonia.Methods: We recruited young people with high (N=50) and low (N=88) depression symptoms and assessed their learning, consummatory, anticipatory, and motivational responses within an effort and reward learning task. To increase the reward attractiveness, especially for younger people, we included not only money (secondary reward), but also chocolate tastes and puppy images (primary rewards).Results: Across all participants, we found that self-reported willingness to exert effort positively correlated with actual effort exertion and negatively with effort completion times. We also observed higher accuracy for reward learning vs. effort learning. Additionally, effort expenditure differed between reward types, although no differences in reward liking were observed. Interestingly, we also found that higher anticipatory anhedonia was associated with lower reward learning accuracy. Limitations: The study assessed only depressive symptoms, not clinically diagnosed major depression. Conclusion: To our knowledge, this is the first study to examine reward and effort learning simultaneously in young people with depression symptoms. Our findings suggest a differentiation between motivational and consummatory responses, as well as between reward and effort learning. Moreover, we show that anticipatory anhedonia is related to reward learning. Understanding the link between objective reward processing and anhedonia sub-types could provide new targets for treatment development.

Aberrant reward dynamics in trait anticipatory anhedonia

As a cardinal feature of several psychiatric disorders, anhedonia includes a consummatory component (deficits in hedonic response to rewards) and an anticipatory component (a reduced motivation to pursue them). Although being conceptualized as impairments of reward system, the neural characterization of reward processing in anhedonia is hampered by the enormous heterogeneity in the reward phase (‘wanting’ vs ‘liking’) and comorbidity (inherent to disease states). The current event-related potential (ERP) study examined the reward dynamics of anticipatory anhedonia in a non-clinical sample. Anticipatory and consummatory ERP components were assessed with a monetary incentive delay task in a high anticipatory anhedonia (HAA) group and a low anticipatory anhedonia (LAA) group. HAA vs LAA group showed a diminished reward-related speeding during behavioral performance and reported overall reduced positive affect during anticipation and receipt of outcomes. Importantly, neural dynamics underlying reward processing were negatively associated with anticipatory anhedonia across the anticipatory phase indexed by the contingent negative variation and the consummatory phase indexed by the feedback P3. Our results suggest that anticipatory anhedonia in non-clinical individuals is linked to a poor modulation during both anticipatory and consummatory phases of reward processing.

Measurement of negative and depressive symptoms: Discriminatory relevance of affect and expression

There is conceptual overlap between negative and depressive symptoms: Mainly the ‘avolition’ factor of negative symptoms also encompasses main symptoms of depression. However, whereas in depression mood is low, mainly anticipatory anhedonia can be found in negative symptoms. Moreover, patients with schizophrenia (SCZ) show greater expressive deficits than those with Major Depressive Episode (MDE). We investigated if measures of depressive and negative symptoms differentiate SCZ subjects, subjects with MDE, and healthy controls (HC). 21 SCZ, 22 MDE, and 25 HC subjects were examined with a rater assessment and a self-rating for negative symptoms (Clinical Assessment Interview for Negative Symptoms (CAINS); Motivation and Pleasure – Self-Report (MAP-SR)) and depressive symptoms (Hamilton Rating Scale for Depression (HAMD-17); Beck Depression Inventory (BDI)). All measures differentiated the psychiatric samples from HC (all p’s < 0.01). The ratings of depressive symptoms (HAMD-17, BDI) and rater assessment of negative symptoms (CAINS) – specifically its sub scale measuring expressive deficits – managed to discriminate between subjects with schizophrenia and those with MDE (SCZ > MDE > HC for negative, MDE > SCZ > HC for depressive symptoms, all p’s < 0.05). The self-rating of negative symptoms (MAP-SR) did not. To differentiate negative symptoms and depression clinicians might look for (self-)reported low mood and observer-rated reduction in speech as well as in gestures and facial expression. Reduced expression and moderate levels of depression point towards a negative syndrome, whereas mostly unimpaired expression and high scores of self-reported depressive symptoms are more likely to indicate a depressive syndrome.