Masterson (1985) conceptualizes the self-destructive, acting-out behaviours of BPD individuals as attempts to manage their feelings  of „abandonment depression“, which include rage, anxiety, fear of being alone, and depression, accompanied by a functional loss of soothing introjects and transitional objects. Accordingly, it is this individuation-separation threat (which may also be triggered by symptomatic improvement in treatment) that is thought to reactivate the „abandonment depression“ of earlier experiences. This, in turn, often invokes the primitive, defenses of projective identification, splitting, and denial leading to the following manifestations: (1) Acting-out, impulsive, self-destructive behaviours; (2) emotional dysregulation, e.g.,, inappropriate anger, lability of affect; (3) unstable, intense interpersonal relationships; and (4) identity disturbances and unstable self-boundaries predisposing to transient psychotic episodes. This triad of the separation-individuation threat leads to abandonment depression that results in the activation of destructive defenses with their associated clinical manifestations constitutes Mastern’s conceptualization of the core dynamic features of borderline phenomena.

Dr. Mervin Smucker is an international trauma consultant and author of numerous articles and books on trauma and cognitive-behavioural therapy interventions.