06 Jul Alterations in Reward Function Precede Psychotic Disorders
MedicalResearch.com Interview with:
Thomas M. Lancaster, PhD
Neuroscience and Mental Health Research Institute
Cardiff University Brain Imaging Research Centre
Cardiff University, Cardiff, United Kingdom
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Psychotic disorders such as schizophrenia and bipolar disorders are heritable. Part of this genetic risk may be conferred by the combined effects of common risk alleles identified via genome wide association studies. Individuals with psychosis are also more likely to experience alterations in the ventral striatum (VS); a key node in the brain’s reward processing network. We hypothesized that common genetic risk for psychosis may confer risk via alterations in the VS. Using functional magnetic resonance imaging (fMRI) data from an adolescent sample (the IMAGEN cohort), we showed that increased psychosis risk was associated with increased BOLD (blood oxygen level dependency) in the VS, during reward processing.
MedicalResearch.com: What should readers take away from your report?
Response: Common risk alleles for psychosis may explain ~1% of the variability in the VS BOLD response to rewarding stimuli in healthy adolescents. This data supports an idea that alterations in reward function are antecedent to psychotic disorders, rather than a consequence of the illness.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: This ‘reward response’ is linked to various symptoms in psychotic disorders (such as loss of pleasure, loss of motivation, apathy). These symptoms are largely refractory to therapies and predict future disease burden and chronicity. Understanding the (patho) physiology of the reward response will give us insight into these symptoms. If we can identify the biological mechanisms by which these genetic risk loci shape the VS BOLD response, we could develop novel treatments, specifically for these symptoms and identify individuals with increased risk.
MedicalResearch.com: Is there anything else you would like to add?
Response: These results are preliminary and will need to be replicated in independent samples.
We plan to conduct follow-up studies to observe how genetic risk shapes the reward response from adolescence into early adulthood. We will also note how these changes relate to clinical symptoms.
MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
Lancaster TM, Linden DE, Tansey KE, et al. Polygenic Risk of Psychosis and Ventral Striatal Activation During Reward Processing in Healthy Adolescents. JAMA Psychiatry. Published online July 06, 2016. doi:10.1001/jamapsychiatry.2016.1135.
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