Positive symptoms: hallucinations (auditory/visual), delusions, disorganized speech (formal thought disorder)
Negative symptoms: lack of emotional response, lack of motivation, lack of interaction
Medications that we learn about help (positive/negative) symtpoms of schizophrenia more
Subtypes of schizophrenia
Catatonic: alternating periods of immobility and excited agitation
Paranoid: delusions of grandeur
Hebephrenic: silly and immature emotionality with disorganized behavior
Undifferentiated: doesn't meet criteria of other subtypes
Disorganization of cells in which brain region is found in schizophrenia?
Dopaminergic cells are very commonly found in which two brain structures?
Mesostriatal dopaminergic cells: What are they, what illnesses associated with them?
Go from substantia nigra to striatum
Associated with Parkinson's
Mesolimbic dopaminergic cells: What are they, what illnesses associated with them?
Go from VTA to limbic system
Schizophrenia and drug abuse
Mesocortical dopaminergic cells: What are they, what illnesses associated with them?
Go from VTA to cortex
Negative symptoms of schizophrenia
Antipsychotics tend to be antagonists of which 2 receptors?
D1 and D2 receptors are (ionotropic/metabotropic)
Neurodevelopmental model of schizophrenia and how it explains positive and negative symptoms
Decrease in innervation of VTA from PFC (reduced mesocortical function), associated with negative symptoms
This removes inhibitory feedback on limbic structures, causing positive symptoms
Blockade of both D2 and 5-HT2 receptors - advantage?
In striatum, 5-HT stimulation of 5-HT2 receptors blocks dopamine. So 5-HT2 blockade increases dopamine in striatum
5-HT2 blockade doesn't have much effect in limbic system
D2 blockade in striatum leads to movement disorder side effects; a drug that blocks 5-HT2 and D2 antagonizes dopamine in limbic system but not as much in striatum; REDUCED MOVEMENT DISORDER SIDE EFFECTS
D2 blockade leads to ___________ side effects
In which brain area does D2 blockade lead to movement disorder side effects?
Phenothiazines (such as chlorpromazine)
Butyrophenones (such as halperidol)
Side effects of old antipsychotics
Extrapyramidal side effects
4 extrapyramidal side effects associated with old antipsychotics
Akathisia: internal restlessness
Acute dystonia: spasming of a muscle group
Parkinsonism: tremor, muscle rigidity
Tardive dyskinesia: late acting, repetitive, uncontrollable movements (often in face)
To reduce Parkinsonian side effects, use ____________. Why does this work? These drugs also help with what other side effect of old antipsychotics?
Blocking D2 with antipsychotic like the degeneration of DA cells in substantia nigra in Parkinson's, leading to Parkinsonian side effects
Loss of DA in substantia nigra --> less inhibition of ACh in striatum
Anticholinergics block ACh, reducing symptoms
Anticholinergics also help with acute dystonic reactions
Compazine: What is it?
Old generation phenothiazine
Compazine: What does it do?
Reduces nausea/vomiting by blocking D2 receptors
Someone gets an acute dystonic reaction but never had psychosis. What was this person on and why? How do you reduce these side effects?
Reduce nausea and vomiting
Reduce acute dystonia with anticholinergics
Haldol-D: What is it? What are advantages and disadvantages?
Haldol-decanoate; slow IM form of Haldol, has a very long half-life (couple of weeks or so)
Advantages: Ensures patient receives medication, allows you to give ~1 injection per month (easier than a pill everyday)
Disadvantages: You can't stop once you're on it; if you have a severe side effect, sucks to suck
Common side effect of new generation antipsychotics?
Metabolic syndrome side effects (weight gain and other risk factors for heart disease/diabetes)
A "truly different" antipsychotic; helpful, but many side effects and potentially dangerous
A new generation antipsychotic that has also been approved by the FDA for depression treatment