Schizophrenia

Question 1

What are the safeguards in place to protect people from over-diagnosis?

Answer 1

Have the symptoms for a minimum of 6 months and have at least 2 positive symptoms

Question 2

What is the evidence on genetic vulnerability?

Answer 2

DZ twins: 17%
MZ twins: 48%
Offspring of 2 schizophrenics: 46%

Question 3

What are the differences between type I and type II schizophrenia?

Answer 3

Type I: positive symptoms, neurochemical imbalance, excess dopamine
Type II: negative symptoms, associated with neuroanatomical degeneration, enlarged lateral ventricles and a reduced size of frontal and temporal lobes, amygdala, hippocampus

Question 4

What is the dopamine hypothesis?

Answer 4

• suggests that schizophrenia involves excess dopamine activity, positive symptoms could be due to excess dopamine activity
• dopamine agonists (amphetamine, L-Dopa) can generate psychosis
• typical antipsychotics (chlorpromazine and haloperidol) block D2 type dopamine receptors
• drugs that block dopamine appear to be effective in treating the positive symptoms but not negative symptoms

Question 5

What is the difference between the action of typical and atypical antipsychotics?

Answer 5

Atypical (clozapine, risperidone): block fewer D2 dopamine receptors and some types of serotonin receptors, more effective on positive and negative symptoms (much better side effects), clozapine can produce a white blood cell disorder (agranulocytosis)

Question 6

Appreciate that drug treatment is only moderately effective

Answer 6

14% first time sufferers and 25% of repeat sufferers do not response adequately to antipsychotics, 25-50% who benefit from drugs continues to have positive symptoms, could be due to non-compliance, drugs only help moderate symptoms, they don’t help cure it

Question 7

Understand the logic of the fornito et al (2011) study and how it demonstrates deterioration of neuronal connectivity in schizophrenia

Answer 7

• he used an AX continuous task to isolate differences in functional connectivity between schizophrenics and controls
• only when the cue is A and the probe is X, the button pressed should be the index finger on the right hand, everything else is the middle finger
• greater functional connectivity in patients than in controls
• reductionist in connectivity in schizophrenics occur in brain networks involved in executive function
• studies like this show that schizophrenia is a disorder of mental coordination