Happy Friends, Positive Minds! Study Protocol for an Observational Study Examining Co-Rumination and Internalizing Problems in Dutch Adolescent Girls.

Co-rumination is an interpersonal emotion regulation strategy that becomes more prominent in friendships during adolescence, especially for girls. It is a pattern of excessive, pervasive negatively focused interactions about personal problems or distressing experiences that extends a helpful point. A major aspect of co-rumination is self-disclosure; the sharing of personal thoughts and emotions with a close friend. This process strengthens the closeness and enlarges the experienced friendship quality, causing youth to continue using this strategy. However, ample studies also show associations between co-rumination and internalizing problems. Interestingly, not all youth who frequently engage in co-rumination display high levels of internalizing problems. Therefore, the current study uses a real-time observational design to gain more in-dept insights in co-ruminative conversations between Dutch adolescent girls and under which circumstances girls are at risk of developing internalizing problems due to co-rumination. We will use an observational repeated measures design to study co-rumination in 150 female friendship dyads (N = 300 girls) aged 13 to 15 years, with an interval of six months between T1 and T2. Co-rumination will be observed using the Problem Talk Task, developed by Rose (2014) and with self-reports, using the CRQ-short. The association between co-rumination and internalizing problems and friendship quality will be analyzed using multilevel models. Latent transition analysis will be used to identify girls that are especially vulnerable to the negative outcomes of co-rumination. The results of this study will indicate at which girls our developed school based intervention program aimed at reducing co-rumination should be targeted.