Schizophrenia Flashcards
What are the positive symptoms?
Disorders of thought/disorganised behaviour
Hallucinations
Paranoia
What are the negative symptoms?
Blunted emotions
Social withdrawal
Loss of energy
Cognitive impairment
What is schizophrenia?
Disease of the process of thought + perception
What are the contributing factors?
Nutrition of mother when in utero
Obstetric complications
Childhood trauma
Social connections
Infection
Drug misuse
What was the 1st anti-psychotic?
Chlorpromazine
What is suggested that the positive symptoms are due to?
Excess dopamine
Which receptor are the most important?
D2
D3 = negative symptoms
Why do you often get side effects with the medication?
Because they can’t specifically target D2
What is the 1st pathway targeted by antipsychotics?
Mesolimbic pathway
What is the location of the mesolimbic pathway?
Projects from ventral tegmental area (VTA)
What happens if there is hyperactivity in the mesolimbic pathway?
Positive symptoms - eg. hallucinations
What happens when you block the mesolimbic pathway?
Treats positive symptoms
BUT can blunt pleasure
What are the side effects of blocking the mesolimbic pathway?
Lack motivation
Lack of interest
Lack of joy
What is the 2nd pathway targeted by antipsychotics?
Mesocortical pathway
What is the location of the mesocortical pathway?
Pre-frontal area
Projects from VTA
What happens if there are hyperactivity in the mesocortical pathway?
Negative symptoms
What happens if you block the mesocortical pathway?
May make negative symptoms + cognition worse
What is the 3rd pathway targeted by antipsychotics?
Nigrostriatal pathway
What is the location of the nigrostriatal pathway?
Projects from substantia nigra
What happens if there is hyperactivity in the nigrostriatal pathway?
Tics
Dyskinesia
What happens if you block the nigrostriatal pathway?
Dystonia (stiffness)
This is called an EPSEs
What is an EPSE?
Extra pyramidal side effect
How does tardive dyskinesia happen?
Chronic blocking of D2 in nigrostriatal pathway
= facial + tongue movements
= limb movements
What is the 4th pathway targeted by antipsychotics?
Tuberoinfundibular pathway
What is the location of the tuberoinfundibular pathway?
Projects from hypothalamus
What happens if you block the tuberoinfundibular?
Leads to hyperprolactinemia
What will the ideal antipsychotic do?
Decrease dopamine in mesolimbic to treat positive
+
Increase dopamine in mesocortical to treat negative
Whilst also
Leaving dopamine tone unchanged in both nigrostriatal + tuberoinfundibular
What are the side effects of M1 cholinergic receptors?
Dry mouth
Blurred vision
Constipation
Cognitive blunting
