Substantial evidence has suggested the existence of an anhedonia paradox in schizophrenia. Patients with schizophrenia have been found to exhibit an impairment in trait hedonic capacity (i.e., measured by self-reported scales/ clinical interview), but their state hedonic experience, as measured by laboratory tasks, appears to be unaffected.

To find out the underlying psychopathological mechanism of this anhedonia paradox, Dr. Raymond Chan's team at the Institute of Psychology of Chinese Academy of Sciences, working with their international collaborators, examined whether anticipatory pleasure presence in both patients with established schizophrenia and individuals with schizotypy. The finding was published online in Schizophrenia Research.

In this study, researchers administered the Monetary Incentive Delay (MID) task to two independent samples comprising 44 schizophrenia patients and 46 matched healthy controls, and 30 individuals with high schizotypy and 35 with low schizotypy.

Patients with schizophrenia were not found to exhibit impaired consummatory pleasantness to receipt of reward received or loss avoidance. As expected, they (particularly male patients) reported less pleasantness and arousal to future rewards compared to healthy controls.

For individuals with high schizotypy, they predicted more arousing experience to high-rewards than individuals with low schizotypy. Moreover, the negative dimension of schizotypy predicted low levels of pleasantness and arousal towards future rewards.

Taken together, the results suggested that the emotional (anhedonia) paradox in schizophrenia could be partially accounted for by the dissociation between anticipatory and consummatory pleasure.

The study was supported by the National Science Fund China, National Key Research and Development Programme, the Beijing Municipal Science & Technology Commission Grant, and the Beijing Training Project for the Leading Talents in Science and Technology.