Schizophrenia

Question 1

How much of the population does schizophrenia affect?

Answer 1

→ 1%

Question 2

What gender is affected more?

Answer 2

→ men are more affected

Question 3

What are positive symptoms in schizophrenia?

Answer 3

→ increase in abnormal behaviour in addition to normal behaviour

Question 4

What are negative symptoms in schizophrenia?

Answer 4

→ absence of normal behaviour

Question 5

What are cognitive symptoms in schizophrenia?

Answer 5

→ problems with thought processes

Question 6

What are examples of positive symptoms?

Answer 6

→ hallucinations
→ delusions
→ disorganised thought/speech
→ movement disorders

Question 7

What are examples of negative symptoms?

Answer 7

→  social withdrawal
→  anhedonia
→  lack of motivation
→  poverty of speech 
→  emotional flatness

Question 8

What are examples of cognitive symptoms?

Answer 8

→ impaired working memory
→ impaired attention
→ impaired comprehension

Question 9

How long must symptoms last for?

Answer 9

→ 6 months

Question 10

If an identical twin has schizophrenia what is the likelihood of the other twin having it?

Answer 10

→ 50%

Question 11

What are 3 candidate genes for schizophrenia?

Answer 11

→ COMT
→ DISC1
→ GRM3

Question 12

What are 4 pregnancy complications that can lead to schizophrenia?

Answer 12

→ low birth weight
→ premature birth
→ asphyxia
→ influenza

Question 13

What are the 4 types of stress that can contribute to schizophrenia?

Answer 13

→ moving country
→ bereavement
→ loss of job/home/relationship
→ physical/emotional/sexual abuse

Question 14

What kind of drug use can contribute?

Answer 14

→ cannabis
→ amphetamine
→ cocaine
→ LSD

Question 15

What is the evidence for the dopamine hypothesis for schizophrenia?

Answer 15

→ DA is only released in mesocortical and mesolimbic not nigrostriatal
→ D2 agonists produce stereotyped behavior
→ Reserpine depletes DA and controls +ve symptoms
→ antagonist of the D2 receptor has antipsychotic effects
→ Amphetamine increases DA release in schizophrenics which makes the disease worse

Question 16

What is the evidence against the dopamine hypothesis?

Answer 16

→ No change in DA receptors in drug free patients

→ No change in CSF HVA concentration

Question 17

What are the 3 structural differences in schizophrenic brains?

Answer 17

→ brain is slightly smaller
→ grey matter is reduced
→ enlarged ventricles and smaller hippocampus

Question 18

What are the 6 reasons that contribute to the pathophysiology of schizophrenia?

Answer 18

→ Dopamine hypothesis
→ Brain structure differences
→ Hypofrontality
→ NMDA receptor hypofunction
→ Oxidative Stress

Question 19

WHat is hypofrontality?

Answer 19

→ Reduced blood flow to the frontal cortex → reduced activity

Question 20

What is the evidence for the glutamate hypothesis?

Answer 20

→ NMDA antagonists (PCP and ketamine) cause hallucinations and psychotic symptoms
→ Decreased glutamate receptor density in the prefrontal cortex
→ transgenic mice have decreased NMDA receptors and have decreased social interactions

Question 21

What does NMDA hypofunction enhance and reduce?

Answer 21

→ enhances mesolimbic DAergic activity

→ reduces GABA striatal neuron activity

Question 22

What are the effects of Glutamate and Dopamine on GABA receptors?

Answer 22

→ Glutamate - excitatory

→ dopamine - inhibitory

Question 23

What does too little glutamate and too much dopamine cause in the brain?

Answer 23

→ uninhibited sensory input to limbic areas

Question 24

What is the evidence of the effect of 5-HT on schizophrenia?

Answer 24

→ LSD - partial 5-HT agonist causes hallucinations
→ many antipsychotics antagonise 5-HT receptors
→ 5-HT activates DA pathways

Question 25

What does 5-HT2A antagonism cause?

Answer 25

→ antipsychotic effect | → reduce movement disorder side effects

Question 26

What is the main current theory for schizophrenia?

Answer 26

→ over stimulation mesolimbic of D2 receptors → Hypoactivity of frontal cortical D1 receptors → reduced pre frontal glutaminergic activity → 5-HT involved

Question 27

What are the two categories of antipsychotics?

Answer 27

→ typicals | → atypicals

Question 28

What do typicals do?

Answer 28

→ antagonise D2 receptors

Question 29

What do atypicals do?

Answer 29

→ 5-HT2A agonists and D2 agonists

Question 30

Why are atypicals better than typicals?

Answer 30

→ they produce fewer side effects and are more effective at treating the negative symptoms → typicals are only effective in treating positive symptoms

Question 31

What are the effects of a D2 blockade on the nigrostriatal pathway?

Answer 31

→ Parkinsonian like symptoms → Dystonia → Akinesia → Tardive Dyskinesia

Question 32

What are the endocrine effects of a D2 blockade?

Answer 32

→ Breast swelling → Lactation → Impotence

Question 33

What are the effects of a D2 blockade on the mesocortical pathway?

Answer 33

→ Loss of motivation and reward pathways | → sedation

Question 34

What are the effects of a D2 blockade on mesolimbic pathway?

Answer 34

→ Decreased hallucination and treats positive symptoms

Question 35

What other receptors do antipsychotics block other than D2?

Answer 35

→ Muscarinic → histamine → alpha adrenoceptos → 5-HT

Question 36

What is the effect of an alpha adrenoceptor blockade?

Answer 36

→ Postural hypotension → nasal congestion → hypothermia

Question 37

What is the effect of a muscarinic blockade?

Answer 37

→ Dry mouth → blurred vision → constipation → urinary retention

Question 38

What is the effect of blocking H1 and 5-HT?

Answer 38

→ H1 - sedation | → 5-HT weight gain + photosensitisation

Question 39

What does prolactin do?

Answer 39

→ promotes milk production

Question 40

What are two schizoaffective disorders?

Answer 40

→ schizophrenia | → bipolar

Question 41

What is the phase before the disease characterized by?

Answer 41

→ social isolation → interest in fringe cults → social withdrawal

Question 42

What are the 4 phases of schizophrenia?

Answer 42

→ prodrome - late teens/early twenties mistaken for depression and anxiety → Active acute phase - onset of positive symptoms, differentiation between what is and isn’t real is difficult → remission - returning to normality → Relapse

Question 43

What are the requirements for a schizophreniform disease?

Answer 43

→ positive symptoms for at least a month but under 6 months

Question 44

What are the 4 kinds of auditory hallucinations?

Answer 44

→ voices talking about them in 3rd person → voicew talking to them → voices giving running commentary →voiced echoing thoughts

Question 45

What is a delusion?

Answer 45

→ a fixed belief not consistent with cultural norms

Question 46

What are the two states of behavior that schizophrenics exhibit?

Answer 46

→ hyperactivity - destructiveness | →impulsive behavior - murder

Question 47

What cognitive defects do schizophrenics have?

Answer 47

→Decreased responsiveness to emotional issues. →Incongruous affect →Expression of affect inappropriate to circumstances.

Question 48

What are negative symptoms caused by?

Answer 48

→ decreased dopamine activity in the mesocortical system → decrease in D1 → Decrease in glutamate (NMDA)

Question 49

What are positive symptoms caused by?

Answer 49

→ Increased dopamine activity in the mesolimbic pathway | → Increased D2

Question 50

What is the mesolimbic pathway?

Answer 50

→ VTA to → nucleus accumbens → amygdala → hippocampus

Question 51

What is the mesocortical pathway?

Answer 51

→ VTA to cortex

Question 52

What is the tuberohypophyseal pathway?

Answer 52

→ dopamine in anterior pituitary inhibiting the release of prolactin