Impairment in psychosocial functioning increases risk for future onset of eating disorders and a treatment that produced larger reductions in eating disorder symptoms also produced larger improvements in psychosocial functioning. However, no studies have tested whether there is a prospective reciprocal relationship between psychosocial impairment and eating disorder symptoms. Accordingly, the current study tested the hypotheses that baseline psychosocial functioning would predict future increases in eating disorder symptoms and that baseline eating disorder symptoms would predict future increases in psychosocial impairment. These questions were addressed with data from a large sample (N = 1952
M = age 19.7, SD = 5.7) of adolescent girls and young women at high risk for eating pathology due to body image concerns who were followed over a 3-year period. Findings suggest a reciprocal relationship between eating disorder symptoms and psychosocial impairment. Elevated eating disorder symptoms at baseline predicted future increases in psychosocial impairment over 3-year follow-up and elevated psychosocial impairment at baseline predicted future increases in eating disorder symptoms over 3-year follow-up. Both reciprocal effects were small-medium in magnitude (partial η