Translation of positive affect into motivation lacking in schizophrenia
MedWire News: Schizophrenia patients have no deficits in the anticipation, experience, and memory of positive affective events, but they are unable to translate these into motivational states, US scientists have found.
Positive affect can be divided into three temporal stages of anticipation, experience (hedonia), and memory. While it is known that schizophrenia patients can have normal hedonia capacity, the impact of the disorder on the anticipation and memory of positive affect is unclear.
To investigate further, Fabien Trémeau, from the Nathan S Kline Institute for Psychiatric Research in Orangeburg, New York, and colleagues studied 70 schizophrenia patients and 35 unaffected controls, who completed an evocative emotional task.
Ratings of pre-test anticipation, hedonic experience during the test, and post-test remembered pleasures were obtained, along with the patient’s explicit motivation to repeat the test, the team reports in the journal Schizophrenia Research.
There were no significant differences between patients and controls in terms of hedonia, anticipation, and motivation, although schizophrenia patients showed higher remembered pleasure than controls.
On multinomial logistic regression analyses, motivation was significantly predicted by anticipation and remembered pleasure for both groups combined, but the predictive value of hedonia was significantly different between patients and controls.
Further analysis showed that only remembered pleasure predicted motivation in schizophrenia patients, compared with experienced pleasure and remembered pleasure, as well as a trend for anticipation in controls.
They researchers write: “The three major findings of our study are: 1) schizophrenia participants did not differ from healthy subjects on anticipation and on-line experience of pleasure, 2) schizophrenia participants had greater remembered pleasure than controls, and 3) motivation was disconnected from hedonia in schizophrenia.”
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By Liam Davenport