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Budapest, Hungary

Nagy H.,Semmelweis University | Nagy H.,National Institute for Medical Rehabilitation | Levy-Gigi E.,Rutgers University | Somlai Z.,Semmelweis University | And 4 more authors.
Neuropsychopharmacology | Year: 2012

Clinical evidence suggests that after initiation of dopaminergic medications some patients with Parkinson's disease (PD) develop psychotic symptoms, such as hallucinations and delusions. Here, we tested the hypothesis that the neurocognitive basis of this phenomenon can be defined as the formation of arbitrary and illusory associations between conditioned stimuli and reward signals, called aberrant salience. Young, never-medicated PD patients and matched controls were assessed on a speeded reaction time task in which the probe stimulus was preceded by conditioned stimuli that could signal monetary reward by color or shape. The patients and controls were re-evaluated after 12 weeks during which the patients received a dopamine agonist (pramipexole or ropinirole). Results indicated that dopamine agonists increased both adaptive and aberrant salience in PD patients, that is, formation of real and illusory associations between conditioned stimuli and reward, respectively. This effect was present when associations were assessed by means of faster responding after conditioned stimuli signaling reward (implicit salience) and overt rating of stimulus-reward links (explicit salience). However, unusual feelings and experiences, which are subclinical manifestations of psychotic-like symptoms, were specifically related to irrelevant and illusory stimulus-reward associations (aberrant salience) in PD patients receiving dopamine agonists. The learning of relevant and real stimulus-reward associations (adaptive salience) was not related to unusual experiences. These results suggest that dopamine agonists may increase psychotic-like experiences in young patients with PD, possibly by facilitating dopaminergic transmission in the ventral striatum, which results in aberrant associations between conditioned stimuli and reward. © 2012 American College of Neuropsychopharmacology. All rights reserved. Source

Szily E.,Semmelweis University | Keri S.,University of Szeged | Keri S.,National Psychiatry Center
Clinical Psychology and Psychotherapy | Year: 2013

Evidence suggests that emotional processes play an important role in the development of delusions. The aim of the present study was to investigate emotion appraisal in individuals with high and low psychosis proneness. We compared 30 individuals who experienced a transient psychotic episode followed by a complete remission with 30 healthy control volunteers. The participants received the Peters et al. Delusion Inventory (PDI) and the Scherer's Emotion Appraisal Questionnaire. We also assessed the IQ and the severity of depressive and anxiety symptoms. Results revealed that individuals with high psychosis proneness displayed increased PDI scores and more pronounced anxiety compared with individuals with low psychosis proneness. There was a specific pattern of emotion appraisal in individuals with high psychosis proneness. In the case of fear, they achieved higher scores for external causality and immorality, and lower scores for coping ability and self-esteem compared with individuals with low proneness. The PDI scores were weakly related to external causality (r=0.41) and self-esteem (r=-0.37). In the case of sadness and joy, no emotion appraisal differences were found between participants with low and high proneness. These results suggest that individuals who had a history of psychotic breakdown and therefore exhibit high psychosis proneness display an altered appraisal of fear, emphasizing external circumstances, feeling less power to cope and experience low self-esteem. © 2011 John Wiley & Sons, Ltd. Source

Somlai Z.,Semmelweis University | Moustafa A.A.,Rutgers University | Keri S.,National Psychiatry Center | Keri S.,University of Szeged | And 3 more authors.
Schizophrenia Research | Year: 2011

Previous studies investigating feedback-driven reinforcement learning in patients with schizophrenia have provided mixed results. In this study, we explored the clinical predictors of reward and punishment learning using a probabilistic classification learning task. Patients with schizophrenia (n = 40) performed similarly to healthy controls (n = 30) on the classification learning task. However, more severe negative and general symptoms were associated with lower reward-learning performance, whereas poorer general psychosocial functioning was correlated with both lower reward- and punishment-learning performances. Multiple linear regression analyses indicated that general psychosocial functioning was the only significant predictor of reinforcement learning performance when education, antipsychotic dose, and positive, negative and general symptoms were included in the analysis. These results suggest a close relationship between reinforcement learning and general psychosocial functioning in schizophrenia. © 2010. Source

Szily E.,Semmelweis University | Keri S.,University of Szeged | Keri S.,National Psychiatry Center
Journal of Neural Transmission | Year: 2012

The purpose of this study was to investigate the association between the G-703T polymorphism of the tryptophan hydroxylase 2 (TPH2) gene (rs4570625) and emotion appraisal in healthy volunteers. Participants were asked to recall a situation characterized by a strong emotion and to rate appraisal processes: novelty/expectation, pleasantness, goal-conduciveness, fairness, responsibility/ causation, coping ability, morality, and relationship to selfconcept. Results revealed that in the case of fear- and sadness-related autobiographical memories, participants with the GG genotype achieved higher appraisal scores for goal-conduciveness and lower scores for coping ability compared with participants with the TT genotype. In the case of joy, no differences were observed across genotypes. These results suggest that the TPH2 polymorphism affects appraisal processes in the case of negative emotions. © Springer-Verlag 2012. Source

Kovacs T.,National Psychiatry Center | Kelemen O.,Psychiatry Center | Keri S.,National Psychiatry Center | Keri S.,University of Szeged
Psychiatry Research | Year: 2013

The purpose of this study was to investigate Fragile X Syndrome (FXS)-related mechanisms in schizophrenia, including CGG triplet expansion, FMR1 mRNA, and fragile X mental retardation protein (FMRP) levels in lymphocytes. We investigated 36 patients with schizophrenia and 30 healthy controls using Southern blot analysis, mRNA assay, and enzyme-linked immunosorbent assay (ELISA). General intellectual functions were assessed with the Wechsler Adult Intelligence Scale-III, and the clinical symptoms were evaluated with the Positive and Negative Syndrome Scale. Results revealed that, relative to healthy controls, CGG triplet size and FMR1 mRNA were unaltered in patients with schizophrenia. However, the FMRP level was significantly reduced in patients compared with controls. We found an association between lower FMRP levels, reduced IQ, and earlier illness onset in schizophrenia. Chlorpromazine-equivalent antipsychotic dose did not correlate with FMRP levels. These results raise the possibility of impaired translation of FMR1 mRNA, altered epigenetic regulation, or increased degradation of FMRP in schizophrenia, which may play a role in dysfunctional neurodevelopmental processes and impaired neuroplasticity. © 2012 Elsevier Ireland Ltd. Source

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