Reduced frontostriatal response to expected value and reward prediction error in remitted monozygotic twins with mood disorders and their unaffected high-risk co-twins. Issue 10 (2nd July 2021)

• Record Type: Journal Article
• Authors: Macoveanu, Julian; Meluken, Iselin; Chase, Henry W.; Phillips, Mary L.; Kessing, Lars Vedel; Siebner, Hartwig Roman; Vinberg, Maj; Miskowiak, Kamilla W.
• Is Part Of: Psychological medicine. Volume 51:Issue 10(2021)
• Page Start: 1637
• Page End: 1646
• Publication Date: 2021-07-02
• Subjects: Bipolar disorder -- expected value -- familial risk -- major depressive disorder -- prediction error -- twins; Psychiatry -- Periodicals; Medicine and psychology -- Periodicals; Clinical psychology -- Periodicals; 616.89
• DOI: 10.1017/S0033291720000367
• Languages: English
• ISSNs: 0033-2917

Abstract

Abstract: Background: Depressive episodes experienced in unipolar (UD) and bipolar (BD) disorders are characterized by anhedonia and have been associated with abnormalities in reward processes related to reward valuation and error prediction. It remains however unclear whether these deficits are associated with familial vulnerability to mood disorders. Methods: In a functional magnetic resonance imaging study, we evaluated differences in the expected value (EV) and reward prediction error (RPE) signals in ventral striatum (VS) and prefrontal cortex between three groups of monozygotic twins: affected twins in remission for either UD or BD ( n = 53), their high-risk unaffected co-twins ( n = 34), and low-risk twins with no family history of mood disorders ( n = 25). Results: Compared to low-risk twins, affected twins showed lower EV signal bilaterally in the frontal poles and lower RPE signal bilaterally in the VS, left frontal pole and superior frontal gyrus. The high-risk group did not show a significant change in the EV or RPE signals in frontostriatal regions, yet both reward signals were consistently lower compared with low-risk twins in all regions where the affected twins showed significant reductions. Conclusion: Our findings strengthen the notion that reduced valuation of expected rewards and reduced error-dependent reward learning may underpin core symptom of depression such as loss of interest in rewarding activities. The trend reduction in reward-related signals in unaffected co-twins warrants further investigation of this effect in larger samples and prospective follow-up to confirm possible association with increased familial vulnerability to mood disorders.