Rumination and mindfulness are transdiagnostic risk and protective factors while their role in Premenstrual Dysphoric Disorder (PMDD) is unclear. Thus, we aimed to investigate the cycle-phase-specific effects of rumination and mindful self-focus on momentary mood and cognitions in women with and without PMDD. This study involved brief ambulatory inductions of ruminative and mindful self-focus along with ambulatory assessments of negative (NA) and positive affect (PA), and …