A personality disorder is an enduring, inflexible pattern of inner experience and behavior that deviates markedly from cultural expectations, is pervasive across personal and social situations, begins by adolescence or early adulthood, is stable over time, and causes distress or impairment. The pattern shows up in at least two of four areas: cognition (how self and others are perceived), affectivity (range, intensity, and appropriateness of emotion), interpersonal functioning, and impulse control.

Causes are multifactorial

• Genetic temperament (heritability is moderate for most personality disorders)
• Neurobiology: altered serotonin function and frontolimbic circuits are linked to impulsivity and aggression; amygdala hyperreactivity to emotional cues is described in borderline personality disorder (BPD)
• Environment: childhood abuse, neglect, invalidation, and insecure attachment, especially for BPD and antisocial personality disorder
• Psychodynamic view: rigid reliance on primitive defense mechanisms such as splitting, projection, and denial

DSM-5-TR clusters

Key diagnostic points:

• Antisocial personality disorder requires age 18 or older and evidence of conduct disorder before age 15. Persistent anxiety and depression are not diagnostic features; shallow affect and lack of remorse are typical.
• Obsessive-compulsive personality disorder differs from obsessive-compulsive disorder: the traits feel ego-syntonic (acceptable to the person), without true obsessions and compulsions.
• Schizotypal personality disorder is on the schizophrenia spectrum; transient psychotic-like experiences may occur, but not sustained psychosis.
• DSM-5-TR also contains an Alternative Model (Section III) that rates impairment in personality functioning plus pathological traits; the categorical model above remains the main clinical system.

General approach

• Most clients seek care for another problem (depression, substance use, crisis, self-harm, legal trouble). Look for recurring relationship patterns rather than a single episode.
• Personality traits are ego-syntonic: the client often sees the problem as other people.
• Common co-occurring conditions: depressive and bipolar disorders, anxiety, PTSD, eating disorders, and substance use disorders.

Borderline personality disorder — key behaviors

• DSM-5-TR diagnosis requires at least 5 of 9 criteria
• Splitting: seeing people as all good or all bad, often switching quickly ("You are the only nurse who understands me; the others hate me")
• Frantic efforts to avoid real or imagined abandonment
• Self-injury (cutting, burning), suicidal threats and attempts; lifetime suicide risk is high, so every threat is taken seriously
• Manipulation to meet needs, staff division, intense anger, mood shifts lasting hours, dissociation under stress

Risk assessment

• Suicide and self-harm (method, plan, access to means, previous attempts)
• Violence toward others (antisocial, paranoid)
• Substance use and impulsive behaviors (spending, driving, sex, binge eating)

Personality disorders are generally not diagnosed before age 18, except when features have lasted at least 1 year; antisocial personality disorder cannot be diagnosed before 18.

Psychotherapy is the primary treatment.

• Dialectical behavior therapy (DBT) — best-studied therapy for BPD. Teaches mindfulness, distress tolerance, emotion regulation, and interpersonal effectiveness; reduces self-harm and hospitalization.
• Other evidence-based therapies for BPD: mentalization-based therapy, schema therapy, transference-focused psychotherapy, general psychiatric management.
• Cognitive behavioral therapy (CBT) — challenges core beliefs (e.g., avoidant client testing the assumption "Everyone will judge me").
• Social skills training, group therapy, family psychoeducation.

Pharmacotherapy — symptom-targeted only. No medication is approved by the FDA for any personality disorder. Drugs treat co-occurring disorders or target symptoms, ideally for short periods.

• Avoid benzodiazepines in BPD — risk of disinhibition, dependence, and overdose.
• Prescribe limited quantities to clients at risk of overdose; lithium and tricyclic antidepressants are dangerous in overdose.

Listed in priority order.

1. Safety first
   • Assess suicide and self-harm risk on admission and whenever behavior changes; do not dismiss threats as "attention seeking"
   • Remove means of self-harm; use a written safety plan; provide the level of observation ordered
   • Treat self-inflicted wounds matter-of-factly — provide care without excessive attention, then discuss triggers once the client is calm
   • For aggression: de-escalate early, keep a safe distance and an exit, use restraint or seclusion only as a last resort under policy
2. Validate emotion while keeping safety — when a BPD client threatens self-harm, the priority is to acknowledge the feeling and secure safety, then help the client use a coping skill
3. Consistent limits and boundaries
   • State clear rules and consequences once, calmly, and enforce them every time
   • All staff follow the same plan; hold team meetings to prevent splitting; one primary nurse coordinates care
   • Respond to idealization without accepting a special role: "I am working to understand you. Let's also talk about your relationships with the rest of the team."
   • Do not share personal information or make special exceptions
4. Cluster-specific approaches

1. Teach coping and social skills — emotion regulation, distress tolerance (DBT skills), problem solving, anger management
2. Nurse self-awareness — clinical supervision helps staff manage frustration, avoid rejecting or rescuing, and keep a therapeutic stance

• Explain the diagnosis without blame; describe the disorder as a pattern that can change with treatment
• Practice specific skills: identifying triggers, using a coping plan, delaying impulsive actions, and using crisis lines
• Keep a written safety plan with warning signs, coping steps, contacts, and a crisis number; secure or remove lethal means
• Take medications only as prescribed; do not combine with alcohol or other sedatives; report rash (lamotrigine), abnormal movements or weight gain (antipsychotics), or worsening mood
• Families: learn about the disorder, set consistent limits, avoid reinforcing self-harm, and seek their own support
• Keep follow-up appointments; treatment such as DBT usually lasts a year or more

• Personality disorders are enduring, pervasive, inflexible, and ego-syntonic
• Cluster A = odd (paranoid, schizoid, schizotypal); Cluster B = dramatic (antisocial, borderline, histrionic, narcissistic); Cluster C = anxious (avoidant, dependent, obsessive-compulsive)
• Paranoid → main defense projection; approach honest, polite, non-argumentative
• BPD → splitting, fear of abandonment, self-harm; consistent limits by the whole team; DBT is the leading therapy
• Treat every suicide or self-harm threat seriously; priority is safety
• Antisocial: age 18 or older plus conduct disorder before 15; lack of remorse, not persistent anxiety
• Dependent → promote independent decision making, starting with small choices
• Avoidant → CBT to test negative assumptions about others' judgment
• Narcissistic → give feedback privately, avoid public confrontation
• No FDA-approved drug for personality disorders; avoid benzodiazepines in BPD