The importance of studying psychopathology in subclinical populations

State-dependent alterations of implicit emotional dominance during binocular rivalry in subthreshold depression

Binocular rivalry, a visual perception phenomenon where two or more percepts alternate every few seconds when distinct stimuli are presented to the two eyes, has been reported as a biomarker in several psychiatric disorders. It is unclear whether abnormalities of binocular rivalry in depression could occur when emotional rivaling stimuli are used, and if so, whether an emotional binocular rivalry test could provide a trait-dependent or state-dependent biomarker. In the current study, 34 individuals with subthreshold depression and 31 non-depressed individuals performed a binocular rivalry task associated with implicit emotional processing. Participants were required to report their perceived orientations of the rival gratings in the foreground and to neglect emotional face stimuli in the background. The participants were retested after an approximately 4-month time interval. Compared to the non-depressed group, the subthreshold depression group showed significantly longer perceptual dominance durations of the grating with emotional faces as the background (i.e., implicit emotional dominance) at the initial assessment. However, the abnormality was not found at the follow-up assessment. More importantly, we found smaller changes in depressive severity at the follow-up assessment for individuals displaying longer emotional dominance at the initial assessment than for individuals with weaker emotional dominance. The current emotional binocular rivalry test may provide an objective, state-dependent biomarker for distinguishing individuals with subthreshold depression from non-depressed individuals.

Event-related potentials during the ultimatum game in people with symptoms of depression and/or social anxiety

Depression and social anxiety are common disorders that have a profound impact on social functioning. The need for studying the neural substrates of social interactions in mental disorders using interactive tasks has been emphasized. The field of neuroeconomics, which combines neuroscience techniques and behavioral economics multiplayer tasks such as the Ultimatum Game (UG), can contribute in this direction. We assessed emotions, behavior, and Event-Related Potentials in participants with depression and/or social anxiety symptoms (MD/SA, n = 63, 57 females) and healthy controls (n = 72, 67 females), while they played the UG. In this task, participants received fair, mid-value, and unfair offers from other players. Mixed linear models were implemented to assess trial level changes in neural activity. The MD/SA group reported higher levels of sadness in response to mid-value and unfair offers compared to controls. In controls, the Medial Frontal Negativity associated with fair offers increased over time, while this dynamic was not observed in the MD/SA group. The MD/SA group showed a decreased P3/LPP in all offers, compared to controls. These results indicate an enhanced negative emotional response to unfairness in the MD/SA group. Neural results reveal a blunted response over time to positive social stimuli in the MD/SA group. Moreover, between-group differences in P3/LPP may relate to a reduced saliency of offers and/or to a reduced availability of resources for processing incoming stimuli in the MD/SA group. Findings may shed light into the neural substrates of social difficulties in these disorders.

Dissociation as a Mediator of Traumatic Childhood Experiences and Ideas of Reference

Ideas of reference (IR) - self-attributions about what happens in the social environment are a frequent phenomenon present in a wide variety of people with mental health disorders as well as in the nonclinical population. The purpose of this study was to find out the relationship between traumatic childhood experiences, IR and dissociative states in the nonclinical population, emphasizing the potential mediating role of dissociation between traumatic experiences and IR. The sample was comprised of 337 participants from the general population (58.8% women) with a mean age of 33.20 years (SD = 14.08). They filled in the Juvenile Victimization Questionnaire (JVQ), the Dissociative Experiences Scale-II (DES-II) and the Referential thinking Scale (REF). The results supported the original hypotheses and showed that the participants with higher frequency of IR reported more childhood traumatic (χ² (2) = 64.33, p < .001, f = .39, 1- β = .99) and dissociative experiences (χ² (2) = 50,414, p < .001, f = .38, 1- β = .99), and that dissociative states (β = .12, p < .05; 95%CI [.07, .19]; c´ = .26, p < .001), specifically absorption (β = .09, p < .05; 95% CI [.03, .15]; c´ = .26, p < .001), mediated between traumatic childhood experiences and referential thinking. It was concluded that the relationship between traumatic experiences and IR is complex and may be mediated by variables such as dissociation.