Diagnosis

Question 1

Define a positive symptom

Answer 1

Additional symptoms beyond those of ordinary experience

Question 2

Describe positive symptoms of schizophrenia

Answer 2

• delusions = beliefs that have no basis in reality
• hallucinations = sensory experiences with no basis in reality or distorted perceptions of real thinhd

Question 3

Define a negative symptom

Answer 3

A loss of usual abilities and experiences

Question 4

Describe negative symptoms of schizophrenia

Answer 4

• speech poverty = reduced frequency and quality of speech
• avolition = loss of motivation to carry out goal oriented tasks, results in lowered activity levels

Question 5

Name the two classification systems and how these diagnose SZ

Answer 5

ICD-10 —> 2+ negative symptoms
DSM-V —> 1+ positive symptom

Question 6

How does comorbidity affect classification and diagnosis of SZ?

Answer 6

• comorbity = occurrence of 2 conditions/disorders together
• Buckley et al found 1/2 patients with diagnosis of SZ also had depression or substance abuse
• also found OCD (23%) and PTSD (29%) common
  = reduces validity, questions whether SZ is distinct condition
• reduces validity of diagnosis as difficult to distinguish SZ symptoms so may lead to inaccurate diagnosis

Question 7

How does symptom overlap affect classification and diagnosis of SZ?

Answer 7

• considerable overlap between schizophrenia symptoms and other conditions (e.g. bipolar shares symptoms of delusions and avolition)
  = reduces validity of classification; if many symptoms share symptoms SZ may not be distinct
  = reduces validity of diagnosis, difficult to accurately diagnose individuals with correct disorder

Question 8

How does gender bias affect classification and diagnosis of SZ?

Answer 8

• Julia Longnecker et al found since 1980s men have been diagnosed w SZ more than women, no prior difference
• may be due to female patients functioning better, more able to mask symptoms or display diff symptoms
  = means classification systems are androcentric; symptoms based on male presentations so doesn’t consider difference w women
  = women may be under diagnosed, not receiving correct treatment, reduces validity

Question 9

How does culture bias affect classification and diagnosis of SZ?

Answer 9

• some symptoms of SZ have different meanings in diff cultures (r.h. hearing voices = communicating with ancestors)
• British Afro-carribeans 9x more likely to be diagnosed than british white people, not as high as in African/Carribean countries so not due to genetics
  = suggests classification is ethnocentric ; based on Western views so doesn’t consider difference in cultural values
  = suggests afro-carribeans being over diagnosed and discriminated against

Question 10

How does validity affect classification and diagnosis of SZ?

Answer 10

• Cheniaux had two psychiatrists assess same 100 clients using ICD10 and DSM5
• found 68 diagnosed w ICD vs 39 w DSM
  = reduces validity as either one is under diagnosing or over diagnosing SZ

Question 11

How does reliability affect classification and diagnosis of SZ?

Answer 11

Flávio Osorio - 2 psychiatrists assessed 180 individuals w DSM-V
- pairs of psychiatrists achieved inter-rater reliability of +.97 and test-retest reliability of +.92
= suggests diagnosis of SZ using DSM-V is very reliable