Measuring Change in Attachment Insecurity Using Short Forms of the ECR-R: Longitudinal Measurement Invariance and Sensitivity to Treatment.

Attachment insecurity is important for psychotherapy both as an aspect influencing the therapeutic process as well as potential outcome variable of a treatment. Two German short forms of the Experiences in Close Relationships - Revised (ECR-R) have been proposed to assess individual differences in attachment anxiety and avoidance. In this research, we examined whether these questionnaires are suitable for measuring change in attachment anxiety and avoidance by testing longitudinal measurement invariance in two independent clinical samples (N₁ = 493, N₂ = 273) using a pre-post design. Results indicated that strict longitudinal measurement invariance can be assumed for both measures. Thus, changes in scale scores before and after treatment can be interpreted as changes in the latent dimensions of attachment anxiety and avoidance. Both questionnaires were also sensitive to treatment in that attachment insecurity was overall reduced after therapy. Although both measures appear to be generally suitable for investigating treatment effects, they exhibited consistent problems with structural validity across samples that should be reexamined in future research.