Abstract
OBJECTIVE: To enhance our understanding of the processes of change and the interaction of symptoms, we applied a relatively novel method known as Dynamic Time Warp to data from low-threshold internet-based interventions directed at decreasing eating disorder (ED) symptoms and increasing help-seeking. METHOD: Utilizing data from the Featback study, we examined how various factors such as ED psychopathology, binge eating, vomiting, laxative use, BMI, anxiety, depression, self-efficacy, social support, well-being, and health-related quality of life interplayed over a period of 14 months among 355 individuals at six different time points. Moreover, we explored which symptoms exerted a significant temporal relationship on others (with high out-strength) and which were most affected by other symptoms (with high in-strength). RESULTS: The sample included participants with different types of ED symptoms and high levels of severity. On a group level, we identified four dimensions with similar within-person trajectories: (1) Depression, anxiety, ED psychopathology, health-related quality of life, and self-rated health; (2) binge eating and vomiting; (3) self-efficacy and social support; (4) BMI, well-being, and laxative use. Directed analyses revealed that social support and anxiety had the highest significant out-strength (i.e., temporal lead), indicating their changes preceded those of other factors, while laxative use and well-being were among those that mostly lagged behind those of other items (with significant in-strength). DISCUSSION: Depressive and anxiety symptom severity were strongly connected to ED severity. Social support may be an important factor to address first as it may drive other factors and symptoms in patients with EDs.