Metacognition moderates the relationship of disturbances in attachment with severity of borderline personality disorder among persons in treatment of substance use disorders.

Objectives: Borderline personality disorder traits have been observed to be linked with both insecure attachment styles as well as deficits in mentalizing and metacognition. Less is known, however, about how attachment style does or does not interact with deficits in mentalizing and metacognition to create, sustain, or influence levels of borderline personality disorder traits. In this study, we examined the hypothesis that metacognitive mastery, which is the ability to use knowledge about mental states of self and others to cope with distress and solve social problems, moderates the relationship of anxious attachment style with the severity of borderline personality disorder traits.

Methods: Concurrent assessments were gathered of metacognitive mastery using the Metacognitive Assessment Scale Abbreviated, anxious attachment style using the Experiences of in Close Relationships Scale, and borderline personality disorder traits using the Structured Clinical Interview for DSM-IV Axis II Disorders. Participants were 59 adults in an early phase of recovery from substance use disorders in a residential setting.

Results: Multiple regression revealed that metacognitive mastery moderated the relationship of anxious attachment style with the number of borderline personality disorder traits. A median split of the anxious attachment and metacognitive mastery scores was performed yielding 4 groups. An analysis of covariance revealed that participants with higher levels of anxious attachment and poorer metacognitive mastery had more borderline personality disorder traits did than the other groups after controlling for levels of psychopathology.

Conclusion: Insecure attachment may be associated with higher number of borderline personality disorder traits in the presence of deficits in metacognitive mastery. Patients with substance use and borderline personality disorder traits may benefit from treatment which addresses metacognitive mastery.