Anhedonia is one of the symptoms commonly shared by different mental disorders including schizophrenia, major depressive disorder and bipolar disorder. Recent findings also suggest that patients with such disorders may fail to translate emotional salience into effortful behavior and to maintain motivation to achieve goal-directed behavior in everyday life.
However, most of the previous studies were mainly limited to self-reported measures and examination of patients with only one diagnostic group without comparing to other mental disorders. It is still not clear whether there are significant correlations between the emotion-behavior decoupling with clinical symptoms among different mental disorders.
In order to bridge such a gap of knowledge, Dr. Raymond Chan and his team from the Institute of Psychology, Chinese Academy of Sciences, have collaborated with international collaborators to examine specifically the dissociation between affective experience and motivated behaviors in patients with schizophrenia, major depressive disorder and bipolar disorder.
They have administered a computer-based test to examine the pattern of such dissociation in 42 patients with schizophrenia, 44 major depressive disorder, 43 bipolar disorders and 43 healthy controls. All the participants were also assessed by a set of clinical rating scales capturing anhedonia.
Their findings showed that all the patients with the mentioned disorders exhibited different levels of anhedonia as well as emotion-behavior decoupling. However, only patients with schizophrenia exhibited significantly lower correspondence between self-reported liking and behavior in both desirable and undesirable conditions, suggesting a severe dissociation of affective experience and motivated behavior comparing to healthy controls.
On the other hand, the deficits in emotion-behavior coupling in participants with major depressive disorder (MDD) and bipolar disorder (BD) mainly occurred in undesirable stimulus avoidance, as well as desirable stimulus seeking during evoked responding.
Taken together, these findings suggest that although all three patient groups exhibit a lowered capacity to experience pleasure as well as a lack of motivation, the pattern of emotion-behavior dissociation is different across schizophrenia, bipolar disorder and major depressive disorder.
These findings provide a potentially common psychopathological mechanism of anhedonia and avolition across different mental disorders, which may be helpful for early detection of these disorders and the development of novel interventions. Dr. Chan's team is planning to examine the neural mechanism underlying the observed emotion-behaviour dissociation in patients with these disorders.
This study was supported by grants from the National Science Fund China, the National Key Research and Development Programme, the Beijing Municipal Science & Technology Commission Grant, the Beijing Training Project for the Leading Talents in Science and Technology, the Natural Science Foundation of Shandong Province, and the CAS Key Laboratory of Mental Health, Institute of Psychology.
The paper is now available online in Journal of Abnormal Psychology.
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