Schizophrenia

Question 1

What percentage of the population does schizophrenia affect?

Answer 1

affects 1% of population and mainly in men

Question 2

What is the classification of a mental disorder?

Answer 2

the process of organising symptoms into categories based on symptoms frequently experienced together

Question 3

What are the two systems to classify a mental disorder?

Answer 3

DSM-5 and ICD-10

Question 4

What is the DSM-5 ?

Answer 4

DSM-5 - one positive symptom is enough for diagnosis

• american system,
• continuous signs of disturbance for 6 months

Question 5

What is the ICD-10?

Answer 5

ICD-10 - two negative symptoms are enough for diagnosis -international system
-continuous signs of disturbance for 1 month

Question 6

What are the positive symptoms of schizophrenia?

Answer 6

additional symptoms beyond those of ordinary existence e.g hallucinations and delusions

Question 7

What are hallucinations?

Answer 7

auditory and visual sensations of something that is not really there

Question 8

What are delusions?

Answer 8

known as paranoia and are irrational beliefs

Question 9

What are the negative symptoms of schizophrenia?

Answer 9

loss of usual abilities and experiences e.g speech poverty and avolition

Question 10

What is speech poverty?

Answer 10

reduction in quantity and quality of speech e.g changing topic mid sentence

Question 11

What is avolition?

Answer 11

loss of motivation e.g poor hygiene

Question 12

What are the issues in diagnosis?

Answer 12

Good reliability, co-morbidity, cultural bias, gender bias, symptom overlap

Question 13

Why is there good reliability in the diagnosis of schizophrenia?

Answer 13

Rosenhan’s study, was not valid but ‘patients’ were consistently diagnosed wrong.

7 confederates said that they could hear a voice saying ‘thud, hollow, empty’ which was not a symptom of schizophrenia. 12 hospitals in 5 different states were used + all were admitted to hospital with no confederates being detected.

Question 14

What is comorbidity? + the percentage rates of schizophrenia being diagnosed with another disorder?

Answer 14

this is the extent to which 2+ conditions occur together (questions the validity of classifying the 2 conditions separately)

-50% depression, 47% substance abuse, and 29% PTSD

Question 15

Why is there cultural bias in the diagnosis of schizophrenia?

Answer 15

African-Americans + Afro-Caribbeans are 9 times more likely to be diagnosed due to over-interpretation of positive symptoms, which may be more acceptable elsewhere (hearing voices, being overly emotional)

Question 16

Why is there gender bias in the diagnosis of schizophrenia?

Answer 16

accuracy of diagnosis is gender dependent, women are less likely to be diagnosed due to having closer relationships thus they get support (mask symptoms) but men do not hence women with schizophrenia often function better than men.

Question 17

What is symptom overlap?

Answer 17

2+ conditions share symptoms

Question 18

What are the biological explanations for schizophrenia?

Answer 18

family studies + candidate genes + mutations

Question 19

What are family studies?

Answer 19

risk of schizophrenia increases with genetic similarity with a relative with the disorder e.g 48% risk with identical twin, 17% risk with non-identical, 9% risk with siblings, 6% risk with parents however is only correlational

Question 20

What are candidate genes?

Answer 20

many different genes involved with schizophrenia (polygenic), different combinations of factors can lead to disorder

Question 21

What occurs in a mutation?

Answer 21

mutation in parental dna caused by radiation, poison, viral infection

Question 22

What is Gottesman’s family study ?

Answer 22

Gottesman (1991) found that children with 2 schizophrenic parents = 46% concordance, 1 schizophrenic parent = 13% and sibling = 9%

Question 23

What is Joseph’s twin study?

Answer 23

(Joseph 2004) - MZ’s 40% and DZ’s 7%, MZ’s always higher and the difference between them suggests that schizophrenia is inherited/has a genetic component because MZ’s share 100% of their genes

Question 24

What is Tienai’s adoption study?

Answer 24

(Tienai 2000) - biological mother had schizophrenia, 7% of adopted children did compared to 2% of controls hence child is just as likely to have schizophrenia even if not with biological mother (passed on through genetics)

Question 25

What evidence is there for schizophrenia being influenced by the environment?

Answer 25

genetically DZ’s are the same as ordinary siblings (share 50% genes), thus the rates should be the same but it was found that DZ’s rates were higher (17%) than sibling rates (9%), this suggests that schizophrenia can be influenced by the environment.

Question 26

What is the dopamine hypothesis?

Answer 26

dopamine is a neural correlate of schizophrenia, antipsychotics used to treat parkinson’s disease (associated with low DA levels) thus schizophrenia may be associated with high DA levels, particularly positive symptoms.

Question 27

What results in hallucinations and delusions?

Answer 27

Messages from neurones that transmit dopamine fire too easily/often thus schizophrenics have too many D2 receptors on post synaptic neurones so more dopamine binds and more neurones are fired → leading to hallucinations and delusions.