Personality Disorders and Disruptive Behaviour
What this domain tests
This domain tests accurate trait description, the difference between stable personality dysfunction and an acute episode, and matching psychotherapy to disorder. It also tests disruptive behaviour diagnoses in younger patients.
Core rules and concepts
- DSM-5 clusters: A - paranoid, schizoid, schizotypal; B - antisocial, borderline, histrionic, narcissistic; C - avoidant, dependent, obsessive-compulsive.
- ICD-11 model: severity (mild, moderate, severe) plus trait domains - negative affectivity, detachment, dissociality, disinhibition, anankastia - and an optional borderline pattern qualifier.
- Borderline personality disorder: five of nine criteria (unstable relationships, identity disturbance, impulsivity, affective instability, anger, suicidal or self-harming behaviour, emptiness, dissociation); first-line treatment is structured psychotherapy such as DBT, MBT, schema therapy or transference-focused psychotherapy; long-term prognosis is better than once taught.
- Antisocial personality disorder: age 18 or over with conduct disorder before 15; psychopathy is a narrower construct measured by the PCL-R.
- Disruptive behaviour: oppositional defiant disorder, conduct disorder, intermittent explosive disorder, with limited prosocial emotions as a conduct disorder specifier.
Worked example
A 22-year-old with recurrent self-harm, intense stormy relationships, chronic emptiness and identity confusion meets borderline criteria. The plan is DBT with a written crisis plan; antipsychotics are not a maintenance treatment here.
Traps that cost marks
- Diagnosing personality disorder during an acute mood or psychotic episode.
- Confusing schizoid (low desire for relationships) with avoidant (desire but fear).
- Confusing OCPD (perfectionism, orderliness) with OCD (ego-dystonic obsessions).