Dialectical Behavior Therapy: Borderline Personality Disorder Defense Mechanisms

Symptom Media Discussion 10: Borderline personality disorder and DBT

Before answering, view Borderline Personality Disorder Vol. 1 in the Symptom Media film library (DSM-5-TR, Personality Disorders) and read the article “A Case Study of Dialectical Behavior Therapy for Borderline Personality Disorder” (ResearchGate).

Case: Clare is brought to the ER after slashing her wrist with a razor. She had previously been in the ER for drug overdose and has a history of addictions. She can be sarcastic, belittling and aggressive to those who try to care for her. She has a history of difficulty with interpersonal relationships at her job. Clare is diagnosed with borderline personality disorder. First, identify the defense mechanisms Clare is using, and second, discuss the various dialectical behavioral activities that can be utilized with Clare.

Original example for study purposes.

Defense Mechanisms Clare Is Using

Borderline personality disorder (BPD) is characterized by a pervasive pattern of instability in relationships, self-image and emotions, marked impulsivity and recurrent self-harm or suicidal behavior (American Psychiatric Association [APA], 2022). Clare’s behavior suggests several primitive defense mechanisms common in BPD:

• Splitting: viewing people as all good or all bad. Clare may idealize a nurse one moment and belittle the same nurse the next, which explains her sarcasm and aggression toward caregivers and her unstable work relationships.
• Devaluation and idealization: closely linked to splitting, Clare devalues those who try to help her, protecting herself from feeling dependent or rejected.
• Projection and projective identification: attributing her own anger or self-hatred to others (“You think I’m worthless”) and behaving in ways that provoke staff to react with the rejection she expects.
• Acting out: expressing overwhelming emotions through behavior, such as cutting, overdosing and using substances, rather than words.
• Denial: minimizing the seriousness of her self-harm or addiction.

Recognizing these defenses helps nurses avoid taking Clare’s hostility personally, maintain consistent boundaries and respond with empathy rather than rejection.

Dialectical Behavioral Activities for Clare

Dialectical behavior therapy (DBT), developed by Marsha Linehan, combines cognitive-behavioral strategies with acceptance and mindfulness. Its central dialectic is balancing acceptance (validating Clare’s pain) with change (teaching new skills). Standard DBT includes individual therapy, weekly group skills training, phone coaching for crises and a therapist consultation team (Linehan, 2015). The assigned case study illustrates how this structure helped a client reduce self-harm and improve functioning. For Clare, useful activities include:

• Diary cards: Clare tracks daily urges to self-harm or use substances, emotions and skills used, which guides each therapy session.
• Behavior chain analysis: after an episode such as cutting, Clare and her therapist map the vulnerabilities, triggers, thoughts, emotions and consequences to identify where she could have used a different skill.
• Mindfulness skills: “observe, describe, participate” and finding her “wise mind,” the balance between emotional and reasonable mind, help Clare notice emotions without acting on them.
• Distress tolerance skills: the TIPP skills (Temperature, Intense exercise, Paced breathing, Paired muscle relaxation), distraction with ACCEPTS, self-soothing with the five senses, pros and cons of acting on urges and radical acceptance help Clare survive crises without cutting or using drugs.
• Emotion regulation skills: identifying and naming emotions, “check the facts,” “opposite action” (for example, approaching rather than lashing out when feeling hurt) and PLEASE skills (treating physical illness, balanced eating, avoiding mood-altering drugs, balanced sleep and exercise) reduce emotional vulnerability.
• Interpersonal effectiveness skills: DEAR MAN (Describe, Express, Assert, Reinforce, stay Mindful, Appear confident, Negotiate) helps Clare ask for what she needs at work; GIVE (be Gentle, act Interested, Validate, use an Easy manner) helps maintain relationships; and FAST (be Fair, no Apologies for existing, Stick to values, be Truthful) protects self-respect.
• Safety and crisis planning: a written plan with warning signs, coping skills, contacts and phone coaching, along with integrated treatment for substance use (DBT has adaptations for co-occurring substance use disorders).

In the ER and inpatient setting, nurses can support DBT by validating Clare’s feelings (“It makes sense that you feel overwhelmed”), setting clear and consistent limits, coaching skills during distress and avoiding power struggles. Over time, these skills can reduce self-harm, emergency visits and conflict, helping Clare build what Linehan calls “a life worth living.”

References

American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). https://doi.org/10.1176/appi.books.9780890425787

Linehan, M. M. (2015). DBT skills training manual (2nd ed.). Guilford Press.

[Add the assigned case study article with its full author list, year and journal from the “read full text” version, and the Symptom Media film citation.]