The relationship between defense mechanisms and attachment: a narrative review

While a substantial number of studies investigate the nuances and clinical relevance of attachment styles and defense mechanisms separately, relatively few studies have explored the relationship between attachment styles and defense mechanisms. We aimed to provide a narrative review of empirical studies that used validated measures to assess the relationship between defense mechanisms and attachment styles in adolescents or adults. Twenty peer-reviewed studies published over the past 30 years were included. Except for one study involving high school students, all others focused on adults, mostly from community samples, with a few including clinical populations. Most studies employed various self-report questionnaires, though several used observer-rated or interview-based methods, with the majority using a cross-sectional design; a few studies used experimental and longitudinal designs as well. The studies' findings indicate an association between insecure attachment and greater use of immature defenses, while secure attachment is associated with more mature defenses. Anxious attachment was particularly linked to defenses such as projection, splitting, and devaluation, whereas avoidant attachment was associated with emotional suppression and denial. A subset of studies examined changes in these constructs during psychotherapy, suggesting that both defense mechanisms and attachment security may improve over time, and indicating the potential importance of reflective functioning as a mediator, as well as depressive immature defenses as obstacles to change. These results underscore the clinical relevance of assessing both attachment and defensive functioning and highlight the importance of addressing them as potential mechanisms of change in clinical contexts.