Commentary on Guild et al. (2020): the importance of well-designed intervention studies for advancing attachment theory and its clinical applications

Guild and colleagues (this issue) report results of a long-term follow up after a randomized trial of the effectiveness of an attachment-theory-informed psychotherapeutic intervention for mothers with depression and their toddlers. Their paper shows the intervention can increase the likelihood of secure attachment in children of depressed mothers and that secure attachment explains more optimal social-emotional functioning in middle childhood in the treated group. This commentary discusses the contribution of the paper by Guild and colleagues and their broader body of work to our evolving understanding of developmental processes underpinning social-emotional competence in children of depressed parents, and to several ongoing controversies in the field: 1) the relevance of attachment-theory-informed interventions in the context of maternal depression; 2) the evidence gap regarding the efficacy and effectiveness of attachment-theory-informed interventions, particularly with respect to sustained benefits; 3) cost-benefits of early interventions; and 4) the need for theory driven research that explains how and under what circumstances attachment is related to later child outcomes.