Ecological Validity of Grief Rumination Measures Among Bereaved People.

Grief rumination, characterised by repetitive thinking about the loss and its causes and consequences, is linked to various psychopathological symptoms, including prolonged grief disorder (PGD). Traditional assessments of grief rumination rely on trait self-report questionnaires assessing multiple types of rumination (e.g., reactions, injustice, counterfactuals and meaning), which may be susceptible to memory biases and often fail to capture the dynamic and context-dependent nature of ruminative thoughts. This brief report evaluates the ecological validity of trait versus state grief rumination types using ecological momentary assessment (EMA), testing their convergent and discriminant validity. Bereaved adults (N = 65, 42 women, M_age = 21.88 ± 2.92) completed online measures for 11 types of trait and state grief rumination. The state measures were completed four times a day for 14 consecutive days. We examined the convergent and discriminant validity of these measures through zero-order and multivariate associations. The associations between trait and state grief rumination measures varied between 0.388 and 0.765, but we did not find sufficient evidence supporting the discriminant validity. Multilevel regression analyses further indicated that trait measures of grief rumination captured a fraction of the individual's state grief ruminations. Our findings suggest that trait grief rumination measures may not fully capture the nuances of grief rumination experienced in daily life after loss. We therefore recommend using state measures given they more accurately seem to assess the ebb and flow of grief rumination in real-world settings.