introduction to schizophrenia

Question 1

what is schizophrenia

Answer 1

• 1% of the world population
• more commonly diagnosed in men, urban workers and those of lower classes

Question 2

what are the 2 major systems for diagnosing schizophrenia

Answer 2

DSM- 5
ICD- 10

Question 3

how does the DSM5 diagnosis schizophrenia

Answer 3

one positive symptom

Question 4

How does the ICD diagnose schizophrenia

Answer 4

at least 2 negative symptoms

Question 5

what are positive symptoms

Answer 5

• additional experiences beyond those of ordinary existence
• includes hallucinations and delusions

Question 6

what are hallucinations

Answer 6

• unusual sensory experiences
• some hallucinations are related to events in the environment others are not
• eg hearing voices
• hallucinations can be experienced in relation to any sense

Question 7

what are delusions

Answer 7

• irrational beliefs
• common delusions involve being an important historical political or religious figure
• a person may believe they are under external control

Question 8

what are negative symptoms

Answer 8

• the loss of usual abilities and experience
• includes speech poverty and avolition

Question 9

what is speech poverty

Answer 9

• changes in patterns of speech
• reduction in the amount and quality of speech
• this is sometimes accompanied by a delay in the persons verbal responses during conversation

Question 10

what is avolition

Answer 10

• difficulty beginning or keeping up with goal directed activity
• sharply reduced motivation to carry out activities
• Andreasen (1982) identified 3 signs of avolition : poor hygiene, lack of persistance in work and lack of energy

Question 11

strengthens of diagnosis of schizophrenia

Answer 11

1. good reliability
   - inter- rater reliability and test retest reliability
   - osorio et al (2019) reported excellent reliability for the diagnosis of schizophrenia in 180 individuals using the DSM - 5. pairs of interviewers achieved inter-rater reliability of +0.97 and a test retest reliability of +0.92

Question 12

limitations of diagnosis of schizophrenia

Answer 12

1. low validity
   - criterion validity
   - cheniaux et al (2009) had 2 psychiatrists independently assess the same 100 clients using ICD 10 and the DSM 4 criteria and found that 68 were diagnosed with schizophrenia under the ICD system and 39 under DSM
2. co-morbidity
   - if conditions occur together this calls into question the validity of their diagnosis and classification because they might be a single condition
   - burkley et al found that 1/2 of those diagnosed schizophrenia diagnosed with schizophrenia also had a diagnosis of substance abuse or depression
3. cultural bias in diagnosis
   - symptoms have different meanings in different cultures eg hearing voices
   - black people are 9 times as likely to receive a diagnosis as a white British though people living in African Caribbean are not
   - cultural bias led to an over interpretation of symptoms in black British people (Escobar 2010)