• Research Highlights
People with schizophrenia and other disorders with Symptoms of psychosis often make it difficult to form and maintain social relationships. Most research on the social difficulties that are a core feature of psychotic disorders has focused on brain regions involved in social processing. The role of brain regions involved in social motivation remains largely uncharted territory.
New research funded by the National Institute of Mental Health (NIMH) has found a link between low levels of social motivation in people with psychotic disorders and activity in specific brain regions, identifying a potential neural marker that could help develop diagnostics or treatments for these disorders.
How have researchers examined social motivation in people with psychotic disorders?
This study conformed to the principles of the NIMH Research Domain Criteria (RDoC) initiative. Researchers led by Amy Jimenez, Ph.D., at the University of California, Los Angeles, and William Horan, Ph.D., at the University of California, Los Angeles, and Karuna Therapeutics, aimed to uncover the underlying mechanisms that could explain why many people with psychotic disorders are not motivated to socialize. They examined an aspect of social motivation known as social anhedonia, which is a lack of interest in social connections and decreased pleasure from social situations.
Participants included 71 adults diagnosed with a psychotic disorder, such as schizophrenia or depression with psychotic features. 27 of their adult siblings without psychotic symptoms. and 37 unrelated adults without psychotic symptoms.
At the start of the study, all participants completed a self-report measure of social anhedonia. They then performed a group task while undergoing an fMRI brain scan. The task was designed to closely model social group dynamics in which a correct answer meant the participant gained a point for their group, while an incorrect answer resulted in the loss of a point. Feedback indicating whether their team won or lost each trial task was given in the form of a happy or angry face given by a teammate or an opponent.
The researchers measured brain activity while participants received the feedback in five brain regions that support the social motivation system:
- Ventral striatum
- Orbital frontal cortex
- Island
- Dorsal anterior cingulate cortex
- Tonsil
The researchers examined whether each brain region responded to the type of feedback (win or lose) and the person giving the feedback (teammate or opponent), whether there was a correlation between brain activity and social anhedonia, and whether this correlation differed by group .
What do the results reveal about social motivation in people with psychotic disorders?
All participants showed increased activity in the ventral striatum, orbitofrontal cortex, and amygdala during wins compared to losses, regardless of whether the feedback came from a teammate or an opponent. This finding indicates that people with psychosis, as a group, responded as expected when receiving a reward within a social context.
As expected, individuals with psychotic disorders reported significantly higher levels of social anhedonia compared to siblings and controls without psychosis. Furthermore, among individuals with psychotic disorders, but not their siblings or controls, social indifference was associated with brain activity. Specifically, for people with psychotic disorders, lower activity in the ventral striatum and orbitofrontal cortex was associated with greater social anhedonia. This finding suggests that reduced activity in specific brain regions during social interactions may contribute to some of the social challenges common among people with psychotic disorders.
This study draws attention to an underexplored aspect of how people with schizophrenia and similar disorders experience social interactions. It identifies specific parts of the brain that could play a key role in the social challenges that are a key feature of psychotic disorders. While more research is needed, if replicated, these findings could ultimately lead to improved diagnosis and treatment for people with these conditions.
Report
Jimenez, AM, Clayson, PE, Hasratian, AS, Lee, J., Reavis, EA, Wynn, JK, Green, MF, & Horan, WP (2023). Neuroimaging of social motivation during winning and losing: Associations with social anhedonia across the spectrum of psychosis. Neuropsychology, 188article 108621. https://doi.org/10.1016/j.neuropsychologia.2023.108621
