Relationship between olfactory function and social cognition in euthymic bipolar patients

There is a close functional and neuroanatomical relationship between olfactory ability and emotional processing. The present study seeks to explore the association between olfactory ability and social cognition, especially facial emotion perception, in euthymic bipolar patients. Thirty-nine euthymic outpatients meeting DSM-IV-TR criteria for bipolar disorder and 40 healthy volunteers matched on socio-demographic criteria were recruited. Both groups were assessed at one time point with the University of Pennsylvania Smell Identification Test (UPSIT), the Emotion Recognition Test, and The Faux Pas Recognition Test, as well as measures of general cognition and functioning. The bipolar patients showed a significant impairment in olfactory identification (UPSIT) and social cognition measures compared to healthy controls. Analyses revealed significant relationships between olfactory identification and facial emotion recognition, theory of mind, general cognition, and a trend-level relationship with functioning. Controlling for age and cigarettes smoked, relationships remained significant between olfactory function and facial emotion recognition. There is a deficit of olfactory identification in euthymic patients with bipolar disorder that is correlated with a deficit in both verbal and non-verbal measures of social cognition.