Explicit and implicit attachment and the outcomes of acceptance and commitment therapy and cognitive behavioral therapy for depression

Background Attachment theory predicts that patients who are not securely attached may benefit less from psychological treatment. However, evidence on the predictive role of attachment in the effectiveness of treatment for depression is limited. Methods Explicit attachment styles, levels of attachment anxiety and attachment avoidance, as well as implicit relational self-esteem and implicit relational anxiety were assessed in 67 patients with major depressive disorder (MDD) receiving Acceptance and Commitment Therapy (ACT) or Cognitive Behavioral Therapy (CBT). ANOVA and hierarchical regression analyses were performed to investigate the predictive power of explicit and implicit attachment measures on treatment outcome. Results Explicit attachment avoidance at pre-treatment significantly predicted reduction of depressive symptoms following treatment. Reductions in attachment anxiety and avoidance from pre- to post-treatment predicted better treatment outcomes. Neither attachment style as a categorical variable nor any of the implicit measures significantly predicted treatment outcome. Limitations The sample size is likely to limit the power to detect small effects. Conclusions Our findings suggest that patients with all four attachment styles may profit similarly from psychological interventions. Attachment avoidance as a dimension was shown to play a role in treatment of depression, as were reductions in avoidant and anxious attachment dimensions. Future research should therefore investigate under what circumstances attachment avoidance can lead to better treatment results and if these effects remain in the long term.