Peer co-rumination
Co-rumination reflects the extent towhich the adolescent and friend
repeatedly discuss negative feelings and problems occurring in each
other's lives. This instrument was adapted from a measure developed
by Rose (2002) who found it to be linked to adolescent depressive
symptoms and peer relationship quality. Adolescents used a 5-point
Likert scale (0 = “not at all true” to 5 = “really true”) to rate the
15 items (e.g., “When my friend and I talk about a problem that one of
us has, we will keep talking even after we both know all of the details
about what happened.” “When my friend and I talk about a problem
that one of us has, we spend a long time talking about how sad
or mad the person with the problem feels.”) which are part of
the “rehashing” subscale (i.e., the extent to which the peers repeatedly
discuss the aspects and implications of a problemin detail; Byrd-Craven,
Granger, & Auer, 2011; Davidson et al., 2014). In the current project,we
chose to assess these 15 items and not include the other 12 questions
comprising the “mulling” and “encouraging problem talk” subscales as
the “rehashing” items were conceptually more compatible with
the overall goals and measures of the project. To create the peer corumination
factor, the mean (α = .96) of the 15 items was computed.