P376 Multiple Physiological Measures under External-Erotic Stimulation Delineate Bipolar I and II Disorders

More evidence are needed to separate bipolar disorder types I (BDI) and II (BD II). Characterizing the physiological responses to external-emotional stimuli mediated through cortical to brainstem circuit might help to delineate BD I and BD II. We have invited 38 BD I, 22 BD II and 38 healthy volunteers (controls), to undergo tests of electrooculogram, electromyogram, skin conductance and electrocardiogram under six situational emotional-scenes of pictures and sounds (Disgust, Erotica, Fear, Happiness, Neutral, and Sadness), and their interchanges between background and target presenting orders. We also measured the on-going affective states of these participants. BD I displayed an increased electooculographic activity than BD II did when target Happiness, Neutral and Sadness were presented against the background Erotica. BD II displayed a decreased electromyographic activity than the healthy controls did when target Erotica was presented against background Disgust, Fear, Happiness, Neutral, and Sadness. Moreover, these alterations in patients were not related to their on-going affective states. BD I displayed stronger ocular activity, and BD II displayed weaker muscle activity when responded the situational sexual stimuli. Our study indicates different subtypes of bipolar disorder respond different to external-erotic stimulation, which might be their different endophenotypic markers.