Attachment Anxiety Moderates the Relationship Between Growth in Group Cohesion and Treatment Outcomes in Group Psychodynamic Interpersonal Psychotherapy for Women With Binge Eating Disorder

Previous research suggests an association between increased group cohesion and: (a) improved group process, and (b) improved treatment outcomes for those with binge eating disorder (BED) and depression (Castonguay, Pincus, Agras, & Hines, 1998; Crowe & Grenyer, 2008). Other research indicated that attachment anxiety may be associated with treatment outcomes for women with BED (Tasca, Ritchie et al., 2006). Our goals for this study were to examine the relationship between group cohesion, attachment anxiety, and change in clinical outcomes at posttreatment. Participants, 102 women with BED, were assigned to homogeneously composed psychotherapy groups based on their pretreatment level of attachment anxiety (i.e., high vs. low attachment anxiety). The group treatment was 16 weeks of Group Psychodynamic Interpersonal Psychotherapy (GPIP; Tasca, Mikail, & Hewitt, 2005). Outcomes were measured pre-and posttherapy, and cohesion was measured weekly. We found a significant increase in group cohesion over the course of treatment in both high and low attachment anxiety conditions. We also found that attachment anxiety at study baseline moderated the relationship between growth in group cohesion and change in binge eating. Increase in group cohesion was associated with improved binge eating, but only for those high in attachment anxiety. Our findings are consistent with an interpersonal model of BED, and suggest that group therapists should emphasize the growth of cohesion in therapy groups, especially for those with high attachment anxiety, so as to maximize interventions aimed at reducing binge eating and associated presenting problems.