Describe characteristics and assessment of schizophrenia spectrum and psychotic disorders.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2021). The mark or mark type is shown in brackets.

1. [1] DSM-V defines schizophrenic spectrum and psychotic disorders as sharing one or more of the following:
2. [1] Positive symptoms include beliefs not based in reality / delusions;
3. [1] hallucinations – sensory experiences of things that do not exist;
4. [1] disorganised thoughts/speech;
5. [1] catatonic behaviour;
6. [1] Negative symptoms such as loss of speech (alogia);
7. [1] loss of motivation (avolition);
8. [1] diminished facial/emotion expression;
9. [1] social/emotional withdrawal;
10. [2] Examples could include substance or medication-induced psychotic disorder, schizotypical (personality) disorder, schizoaffective disorder, and catatonia associated with another mental disorder or condition.
11. [2] DSM-V requires two or more symptoms for at least one month. At least one of the symptoms must be delusions, hallucinations or disorganised thoughts/speech.
12. [1] Case studies could include individuals who have been studied in detail.
13. [2] Schizophrenia is diagnosed when individual shows at least two of the following: delusions, hallucinations disorganised speech, disorganised or catatonic behaviour, and flattened affect for at least one month.
14. [1] The individual must show occupational or social functioning that has declined and these symptoms cannot be explained by another medical factor.
15. [2] Delusional disorder is characterised by persistent delusions but whose other behaviours are 'normal'.
16. [1] There is an absence of the other psychotic symptoms of schizophrenia such as hallucinations, disorganised speech or negative symptoms.
17. [1] Some types of delusional disorder are grandiose (belief that they have a (non-existent) unrecognised high status or great skill), persecutory (being conspired against or pursued by those intending to harm), and erotomaniac (belief someone is in love with them).
18. [1] To receive a diagnosis of delusional disorder symptoms must have been experienced for at least one month and be unrelated to physiological effects of substance use.
19. [2] Prior to study, participants completed measures on intellectual functioning (Wechsler Abbreviated Scale of Intelligence) and trait paranoia (Green et al. Paranoid Thoughts Scale (GPTS) Part B) followed by numerous measures on factors in cognitive model of paranoia.
20. [1] Simulator-sickness questionnaire was given before and after the simulation.
21. [2] Virtual reality environment was a 4 min journey on a London underground train populated by computer generated 'neutral' avatars/characters. The avatars breathed and also looked in a variety of directions. There was background tube noise and low-level snippets of conversation.
22. [1] State social paranoia scale was given after the simulation ended as well as qualitative data collected about the participant's experiences.
23. [1] 200 nonclinical members of the general population were used who made comments ranging from positive to neutral to paranoid 'Lady sitting down laughed at me when I walked past'.
24. [1] This shows an unambiguous demonstration of paranoid thinking in the general public.
25. [2] Named issue – validity of definitions/diagnosis – schizophrenia spectrum and psychotic disorders include a variety of different symptoms and no one key symptom is needed for diagnosis.
26. [1] DSM-V and ICD-10 do not ask for the same criteria or longevity of symptoms.
27. [1] Two individuals with very different symptoms could both be diagnosed as schizophrenic.
28. [1] The reliance on self-report measures of a psychotic individual (by definition) may be invalid within a psychotic state.
29. [1] Co-morbidity could also call validity into question in terms of symptom overlap with another condition such as depression.
30. [2] Validity of case studies – this is good because they are in detail and often take place over a long period of time.
31. [1] The validity could be low as not generalisable and the data might be subjective.
32. [2] Validity of Freeman study – Good as a number of measures were taken to assess level of paranoid thinking, social and cognitive traits and emotional distress to compare the results on the virtual reality to.
33. [1] Also good as rather than just interviewing a patient about their symptoms the practitioner can witness the patient in a lifelike environment.
34. [2] However, the ecological validity of the study is not good as it is a simulated environment.
35. [1] On the other hand, it does give some insight into the behaviour of a schizophrenic patient in a much more realistic setting than just asking the patient to describe their symptoms since the practitioner last had an appointment with them.
36. [1] Reliability.
37. [1] Usefulness.
38. [1] Reductionist.
39. [1] Co-morbidity.
40. [1] Gender bias.
41. [1] Cultural bias.