Schizophrenia

Question 1

Schizophrenia

Answer 1

Collection of seemingly unrelated symptoms.

Question 2

DSM-5

Answer 2

One positive symptom must be present

Question 3

ICD-10

Answer 3

Two or more negative symptoms eg avolition or speech poverty

Question 4

Positive symptoms of schizophrenia

Answer 4

Hallucinations -no basis in reality or distorted perceptions of real things.
Delusions - beliefs that have no basis in reality.

Question 5

Negative symptoms of schizophrenia

Answer 5

Avolition - severe loss of motivation.
Speech poverty - reduction in the amount and quality of speech.

Question 6

Issues with diagnosis

Answer 6

Reliability - extent to which diagnosis is consistent.
Inter-rate reliability was poor as Cheniaux studied the diagnosis through two doctors and they varied.
Co-morbidity - occurrence of two illnesses together.
Buckley et al concluded that 50% of people diagnosed wit schizophrenia also have depression.
Cultural bias - African-americans and English people of African origin are much more likely to be diagnosed with Schizophrenia. Many positive symptoms could be seen as normal in African cultures.

Question 7

Genetic basis of schizophrenia

Answer 7

Runs in families - genetic similarities in family members.
Gottesman family study found that MZ twins have 48% shared risk.
Schizophrenia is polygenetic - each gene has an increased risk of schizophrenia.

Question 8

Dopamine hypothesis

Answer 8

Role of dopamine -featured in the functioning of brain systems related to sz symptoms.
Hyperdopaminergia - high dopamine activity in subcortex associated with hallucinations and speech poverty.
Hypodopaminergia - low levels of dopamine in the prefrontal cortex.

Question 9

Neural correlates

Answer 9

Brain activity linked with symptoms - neural correlates are the measurement of structure or function of the brain that correlate with positive or negative symptoms.
Avolition and ventral striatum - involved in anticipation of a reward, loss of motivation could be explained by low activity levels here.
Hallucinations - Allen et found that patients experiencing auditory hallucinations recorded lower activity levels in the superior temporal gyrus.

Question 10

Eval for biological explanations

Answer 10

Strengths

The Gottesman family study shows the genetic similarity conveying the genetic vulnerability.
The role of mutation supports the genetic explanation.
Limitation

Mixed support for the dopamine hypothesis – dopamine agonists that increase dopamine can induce schizophrenic symptoms in people that dont have schizophrenia.
Clear that the environment is also involved - factors such as family functioning during childhood can also play a role in developing schizophrenia.