Borderline Personality Disorder
Borderline personality disorder is the most likely diagnosis given the combination of intense dependence on a close relationship figure, fear of abandonment–type clinging behaviors, and an unstable self-image with identity-driven mimicry of another person’s lifestyle or appearance. [1], [2]
Symptom Pattern Matching
Borderline personality disorder includes frantic efforts to avoid real or imagined abandonment, which aligns with smothering/constant-contact behaviors. [2], [3]
Borderline personality disorder includes identity disturbance, which aligns with mimicking a relative’s appearance and lifestyle. [1], [2]
Borderline personality disorder can involve interpersonal instability and maladaptive relationship behaviors, which can manifest as problematic credibility behaviors such as lying and “victim” presentations in interpersonal conflict. [2], [1]
Key Differential Diagnoses
Dependent personality disorder best fits an excessive need to be taken care of with submissive clinging and fear of separation, but it does not specifically account for identity disturbance or the broader pattern of relational volatility described here. [4]
Histrionic personality disorder includes attention-seeking and suggestibility and can include dependency in interpersonal relationships, but the described smothering and identity-like mimicry pattern is more consistent with borderline personality disorder’s identity disturbance plus abandonment-related behaviors. [5], [2]
Most Likely Diagnosis
Borderline personality disorder is the most likely psychiatric diagnosis for the described presentation. [1], [2]