Anhedonia and amotivation are key clinical features of observed in both patients with schizophrenia (SCZ) and major depressive disorder (MDD). In particular, range adaptive valuation or coding is considered to be one of the factors contributing to anhedonia and amotivation in patients with SCZ. Dr. Raymond Chan and his team from the Neuropsychology and Applied Cognitive Neuroscience (NACN) Laboratory, Institute of Psychology have previously found that dysfunction in range adaptation in individuals along the SCZ spectrum disorders, ranging from patients with established clinical diagnosis to individuals with subclinical features of psychopathology. The team also found that impairments in range adaptation were associated with symptoms of anhedonia and amotivation symptoms in schizophrenia patients at follow-up. However, it is still not fully known whether patients with MDD would also show a similar or distinct range adaptive valuation comparing to patients with SCZ.
In order to address such an issue, Dr. Raymond Chan team and his collaborators further conducted a study to examine valuation of rewards and range adaptive coding in SCZ and MDD patients. In particular, they examined the reward processing constructing and contrasting the representations for expected value (EV) and the outcome value (OV). They administered the Effort-based Pleasure Experience Task to 56 SCZ patients, 46 MDD patients and 56 controls in order to measure the EV and OV adaptation. Their findings showed that both SCZ and MDD patients exhibited altered range adaptation, albeit in different patterns. SCZ patients showed over-adaptation to OV and reduced adaptation to EV. However, MDD patients showed diminished OV adaptation but intact EV adaptation. They also found both OV and EV adaptations correlating with anhedonia and amotivation in these two clinical groups.
Taken together, these findings suggest distinct patterns of range adaptive value representation between SZ patients and MDD patients. Range adaptation to OV and EV may have consistent associations with anhedonia and amotivation symptoms in these two clinical groups. Dr. Chan’s team also suggest these Impaired range adaptations observed in SZ and MDD may be important putative neural mechanisms and potential intervention targets for anhedonia and amotivation for SCZ and MDD patients. Dr. Chan’s team is now taking a transdiagnostic approach to examine the underlying neural mechanism of range adaptive valuation in SCZ, MDD and bipolar disorder based on task-based neuroimaging and magnetic resonance spectroscopy paradigms. They hope these findings will open a new window for us to understand anhedonia and amotivation in psychiatric disorders.
Dr. WANG Ling-ling from the Institute of Psychology and Dr. Simon Lui from the University of Hong Kong are the co-first authors. Dr. Raymond Chan from the Institute of Psychology is the corresponding author. This study was supported by grants from the Scientific Foundation of Institute of Psychology, Chinese Academy of Sciences, the National Key Research and Development Programme, and the Philip K. H. Wong Foundation.
This study was published online on Dec. 28, 2023 in Asian Journal of Psychiatry
- Wang, L. L.#, Lui, S. S. Y.#, So, J. W. L., Hu, H. X., Chu, M. Y., Cheng, K M., Li, S. B., Le, B. L., Lv, Q. Y., Yi, Z. H., Chan, R. C. K.* (2023).Range adaptive value representations n schizophrenia and major depression. Asian Journal of Psychiatry, 92, 103880.
Related publication:
- Wang, L. L., Lam, C. Y. T., Huang, J., Cheung, E. F. C., Lui, S. S. Y., Chan, R. C. K.* (2021). Range-adaptive value representation in different stages of schizophrenia: A proof of concept study. Schizophrenia Bulletin, 47(6), 1524-1533.
- Wang, L, L., Gong, J., Huang, Y., Shi, S., Yan, C., Hu, H., Wang, Y., Lui, S. S. Y., Ju, K.*, & Chan, R. C. K.* (2024). Range adaptation in schizophrenia: A one-year longitudinal study. Schizophrenia Research: Cognition, 35, 100297.
LIU Chen Institute of Psychology
Chinese Academy of Sciences
Beijing 100101, China.
E-mail: liuc@psych.ac.cn
