Psychopathology
What this domain tests
Descriptive psychopathology rewards precision: naming the symptom correctly, separating form from content, and withholding inference until the phenomenon is described. Examiners favour definitions and short vignettes.
Core rules and concepts
- Symptom is reported by the patient; sign is observed by the clinician.
- Delusion (Jaspers): a firmly held false belief, held with extraordinary conviction, impervious to reason or experience, not shared by the patient's culture. An overvalued idea is understandable and less rigidly held. An obsession is intrusive, ego-dystonic and resisted.
- Thought form (stream and connectivity): derailment, tangentiality, loosening of associations, neologisms, clang association, thought blocking, knight's-move thinking. Thought content: delusions.
- Perception: illusion = misperception of a real stimulus; hallucination = perception without a stimulus; pseudohallucination = located in inner subjective space with insight retained; functional hallucination = triggered by a real stimulus in the same modality; reflex hallucination = stimulus in one modality produces a hallucination in another.
- Schneiderian first-rank symptoms: thought echo, thought insertion, withdrawal and broadcasting, delusional perception, made affect, impulse and volition, somatic passivity, and voices arguing or commenting.
Worked example
A woman with OCD fears that touching a door handle will kill her mother. She calls the idea irrational and tries to resist it, so it is an obsession. If she loses that insight and is convinced of it, code OCD with absent insight/delusional beliefs rather than adding a delusional disorder - the belief keeps its obsessive origin.
Traps that cost marks
- Calling every strongly held false idea a delusion, including overvalued ideas.
- Mixing illusion and hallucination.
- Confusing thought blocking (an abrupt interruption) with poverty of speech.
- Describing passivity phenomena without an external agency attributing them.