OBJECTIVE: We conducted a naturalistic study to examine negative affect and dissociative experiences as antecedents to binge episodes. METHOD: Using handheld computers, 33 women with bulimic syndromes provided ongoing self-reports on eating behaviors, affects, and dissociative experiences over 7- to 29-day intervals. RESULTS: Multilevel modeling analyses indicated that negative affect and dissociation were elevated prior to binge episodes. In addition, antecedent effects of dissociation on bingeing were independent of those attributable to negative affect. CONCLUSION: Our results are consistent with models of binge eating that assign a causal role to negative mood and altered self-awareness. As such, our findings imply that binge eating is a multiply determined behavior linked to diverse cognitive and affective processes. (c) 2007 by Wiley Periodicals, Inc.