Neural correlates of the females' susceptibility to negative emotions: an insight into gender-related prevalence of affective disturbances.

Considerable studies reported that females are more susceptible to affective disturbances such as depression, anxiety disorder, and phobia compared to males. Based on the close relation between emotional sensitivity and liability to affective disturbances (Hofer et al. [2006]: NeuroImage 32, 854-862; Spearing [2001]: Bipolar disorder, 2nd ed. Bethesda (MA): National institute of Mental Health), this study investigated the neural mechanism underlying the females' liability to affective disturbances by hypothesizing that females are more susceptible to negative emotions than males. Event-related potentials (ERPs) were recorded for highly negative (HN), moderately negative (MN), and neutral images in Experiment 1, and for highly positive, moderately positive, and neutral images in Experiment 2, whereas subjects (15 males and 15 females) performed a standard/deviant distinction task, irrespective of the emotional valence of deviants in both experiments. In addition to the prominent emotional reactions evoked by HN stimuli in both genders, Experiment 1 displayed conspicuous emotional responses of females to MN stimuli across N2 and P3 components, which were absent in males. In contrast, Experiment 2 demonstrated neither significant valence effect, nor significant valence by gender interaction effect at these components. Thus, although both genders are sensitive to HN stimuli, females, instead of males, are particularly susceptible to negative stimuli of lesser salience, and this female specific susceptibility does not exist to the positive stimuli. Therefore, females must be more susceptible to negative emotions in life settings, which may be one important mechanism underlying their higher prevalence of affective disturbances.