Emotion regulation (ER) has become a relevant construct to understanding paranoia. While the ER strategy called expressive suppression (e.g., poker face) may foster state paranoia by increasing arousal, another strategy called reappraisal (e.g., changing the perspective on situations) may reduce negative emotions and state paranoia when adaptively used. However, if reappraisal fails, this could increase paranoia. The aim of this study was to test the proposed effects of the ER strategies on state paranoia in the socially stressful situation of being excluded in paranoia-prone individuals. We conducted an experimental online study with N=116 participants who were randomized to a social inclusion or an exclusion condition using a virtual Cyberball ball-tossing game. They completed questionnaires on paranoia proneness and habitual ER strategies. Before and after the Cyberball task, participants rated their level of state paranoia. The impact of habitual ER strategies, paranoia proneness, and social stress on changes in state paranoia was investigated using linear regression analysis. The three-way interaction of social stress, paranoia proneness, and habitual reappraisal use significantly predicted state paranoia, t(114)=2.62, p=0.010. The decomposition of the interaction term revealed that in the social stress condition, the impact of reappraisal on state paranoia was moderated by the level paranoia proneness. Specifically, in high paranoia-prone individuals the use of reappraisal predicted higher state paranoia. The findings regarding habitual use of suppression were not significant. Although reappraisal is generally considered a functional strategy, its use in distressing social situations seems to be impaired in persons with higher paranoia proneness. A working model of emotion dysregulation in delusions is presented and possible implications for cognitive therapy of psychosis are discussed.
