Increased sensitivity to positive social stimuli in monozygotic twins at risk of bipolar vs. unipolar disorder

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BACKGROUND: Abnormalities in affective cognition are putative endophenotypes for bipolar and unipolar disorders but it is unclear whether some abnormalities are disorder-specific. We therefore investigated affective cognition in monozygotic twins at familial risk of bipolar disorder relative to those at risk of unipolar disorder and to low-risk twins.

METHODS: Seventy monozygotic twins with a co-twin history of bipolar disorder (n = 11), of unipolar disorder (n = 38) or without co-twin history of affective disorder (n = 21) were included. Variables of interest were recognition of and vigilance to emotional faces, emotional reactivity and -regulation in social scenarios and non-affective cognition.

RESULTS: Twins at familial risk of bipolar disorder showed increased recognition of low to moderate intensity of happy facial expressions relative to both unipolar disorder high-risk twins and low-risk twins. Bipolar disorder high-risk twins also displayed supraliminal attentional avoidance of happy faces compared with unipolar disorder high-risk twins and greater emotional reactivity in positive and neutral social scenarios and less reactivity in negative social scenarios than low-risk twins. In contrast with our hypothesis, there was no negative bias in unipolar disorder high-risk twins. There were no differences between the groups in demographic characteristics or non-affective cognition.

LIMITATIONS: The modest sample size limited the statistical power of the study.

CONCLUSIONS: Increased sensitivity and reactivity to positive social stimuli may be a neurocognitive endophenotype that is specific for bipolar disorder. If replicated in larger samples, this 'positive endophenotype' could potentially aid future diagnostic differentiation between unipolar and bipolar disorder.

Original languageEnglish
JournalJournal of Affective Disorders
Pages (from-to)212-218
Number of pages7
Publication statusPublished - May 2018

    Research areas

  • Adult, Affective Symptoms/genetics, Attention, Bipolar Disorder/genetics, Cognition, Depressive Disorder/genetics, Diseases in Twins/genetics, Emotions/physiology, Endophenotypes, Facial Expression, Female, Humans, Male, Risk, Twins, Monozygotic/genetics

ID: 203249308