作者机构:
[Chan, Raymond C. K.; Yang, Xin-Hua; Wang, Jiao; Huang, Jia; Lui, Simon S. Y.] Chinese Acad Sci, Inst Psychol, Key Lab Mental Hlth, Neuropsychol & Appl Cognit Neurosci Lab, Beijing 100101, Peoples R China.;[Wang, Jiao] Univ Chinese Acad Sci, Beijing, Peoples R China.;[Yang, Xin-Hua] Hunan Agr Univ, Coll Business, Changsha, Hunan, Peoples R China.;[Cheung, Eric F. C.; Lui, Simon S. Y.] Castle Peak Hosp, Hong Kong, Hong Kong, Peoples R China.;[Huang, Jia] Chinese Acad Sci, Inst Psychol, 16 Lincui Rd, Beijing 100101, Peoples R China.
摘要:
Anhedonia is one of the core negative symptoms of schizophrenia that affect the ultimate outcome of this disorder. It is unclear whether the motivational or the hedonic component of anhedonia is impaired in patients with schizophrenia. This study examined the deficits in motivation and hedonic capacity in patients with schizophrenia using an Effort-based pleasure experience task (E-pet). Twenty-two schizophrenia patients with prominent negative symptoms, 18 schizophrenia patients without prominent negative symptoms and 29 healthy controls participated in the present study. All of them were administered the E-pet task, which required the participants to make decisions on whether to choose a hard or easy task based on probability and reward magnitude. When making the grip effort allocation decision, schizophrenia patients with prominent negative symptoms were significantly less likely to choose a hard task than healthy controls. As the reward magnitude and the estimated reward value increased, unlike healthy controls, schizophrenia patients with prominent negative symptoms did not increase their hard task choices. They were also significantly less likely to choose a hard task than healthy controls in medium and high probability conditions. When anticipating potential rewards, these patients reported significantly less anticipatory pleasure than healthy controls, even when reward probability and magnitude increased. The pleasure experience rating after obtaining the actual reward was positively correlated with two pleasure experience scales in schizophrenia patients. In conclusion, patients with schizophrenia, especially those with prominent negative symptoms, showed deficits in both reward motivation and anticipatory pleasure experience. (C) 2015 Elsevier B.V. All rights reserved.
摘要:
Cerebral morphological abnormalities in major depressive disorder (MDD) may be modulated by antidepressant treatment and course of illness in chronic medicated patients. The present study examined cortical thickness in patients with untreated first-episode MDD to elucidate the early pathophysiology of this illness. Here, we examined cortical thickness in patients with first-episode MDD (N=27) and healthy controls (N=27) using an automated surface-based method (in FreeSurfer). By assessing the correlation between caudate volume and cortical thickness at each vertex on the cortical surface, a caudate-cortical network was obtained for each group. Subsequent analysis was performed to assess the effect of anhedonia by the Temporal Experience of Pleasure Scale. We observed increased cortical thickness at the right orbital frontal cortex and the left inferior parietal gyrus in MDD patients compared with healthy controls. Furthermore, morphometric correlational analysis using cortical thickness measurement revealed increased caudate-cortical connectivity in the bilateral superior parietal gyrus in MDD patients. All changes were not related to anhedonia. These preliminary findings may reflect disorder manifestation close to illness onset and may provide insight into the early neurobiology of MDD. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
摘要:
Anhedonia is a hallmark symptom of major depressive disorder (MDD). Preliminary findings suggest that anhedonia is characterized by reduced reward anticipation and motivation of obtaining reward. However, relatively little is known about reward-based decision-making in depression. We tested the hypothesis that anhedonia in MDD may reflect specific impairments in motivation on reward-based decision-making and the deficits might be associated with depressive symptoms severity. In study 1, individuals with and without depressive symptoms performed the modified version of the Effort Expenditure for Rewards Task (EEfRT), a behavioral measure of cost/benefit decision-making. In study 2, MDD patients, remitted MDD patients and healthy controls were recruited for the same procedures. We found evidence for decreased willingness to make effort for rewards among individuals with subsyndromal depression; the effect was amplified in MDD patients, but dissipated in patients with remitted depression. We also found that reduced anticipatory and consummatory pleasure predicted decreased willingness to expend efforts to obtain rewards in MDD patients. For individuals with subsyndromal depression, the impairments were correlated with anticipatory anhedonia but not consummatory anhedonia. These data offer novel evidence that motivational deficits in MDD are correlated with depression severity and predicted by self-reported anhedonia. (C) 2014 Elsevier Ireland Ltd. All rights reserved.