Schizophrenia Flashcards
psychosis
syndrome associated with a variety of illnesses
set of sx in which a person’s mental capacity, affective response, capacity to recognize reality, communicate, and relate to others is impaired.
DSM dx Schizophrenia 6 main sx
Delusions
hallucinations
disorganized speech
grossly disorganized or catatonic behavior
negative symptoms
signs of disturbance for at least 6 months
positive symptoms
delusions
hallucinations
agitation
disorganization
negative symptoms
asociality
affective flattening
alogia
avolition
anhedionia
affective sx
depressed mood
inappropriate
blunted
cognitive sx
poor attention
problems with learning
impaired fluency
5 As
asociality
affective flattening
alogia
avolition
anhedionia
avolition
lack of motivation
kinda looks like depression which is why some dx with depression first
alogia
poverty of speech
4 pathways
mesocortical pathway
mesolimbic pathway
nigrostriatal pathway
tuberoinfundibular pathway
dopamine hypothesis
mesocortical dec D2
mesolimbic inc D2
Nigrostriatal and tuberoinfundibular not affected
mesocortical pathway
Innervates the prefrontal cortex
Which is responsible for personality, executive function
Dec dopamine means behavioral deficits like impaired cognition
this is whats affected in prodromal phase before psychosis
mesolimbic pathway
Brain tries to compensate with excess in mesolimbic
this leads to Psychosis: Hallucinations, delusions, misinterpret our environment
Nigrostriatal pathway
Responsible for movement
normal function but untreated you see tardive dyskinesia etc
But for simplicity we will say its normal
Tuberoinfundibular pathway
Controls hypothalamus, adrenal, pituitary
We know dysregulation including temp and psychogenic polydipsia
But for simplicity we say its kind of normal there
Glutamate
Involved in mult dx and is a key target for rx (esp newer rx) in schizophrenia and depression
Works tandem with dopamine
glutamate requires what to function
Co-transmitter
Needs glycine and D-serine
required on the NMDA receptor for glutamate to function
key glutamate pathways
Prefrontal cortex
Nucleus accumbens
Glutamate hypothesis
Glutamate activity at NMDA receptors is hypofunctional
so you get:
Neurodevelopmental abnormalities
GABA interneurons in the PFC
Glutamate becomes hyperactive
Also glutamate regulates dopamine in the mesolimbic and mesocortical pathways
It innervates the pathways differently
typical antipsychotics started when and with that
1950s
with thorazine
caused neurolepsis but was originally an antihistamine
neurolepsis
Slowness, absence of motor movements, affective indifference
Neuroleptics AKA antipsychotics
typical antipsychotics aka
1st gen
conventional
typical antipsychotic binding sites
- M1 antag
a. muscarinic - H1 antag
a. histamine - Alpha 1 antag
- D2 antag
a. Block the activity of a ligand, stays resting
typical antipsychotic changes to pathways
dec mesocortical pathway MORE
dec mesolimbic which was elevated
dec nigrostriatal and tuberoinfundibular which were unaffected
1st gen effect on pos and neg sx
Treats our positive sx (mesolimbic)
Worsens our negative sx (mesocortical)
when a patient stops their 1st gen
their neg sx improve
they can navigate the world better
Motivation, organization, processing etc are a prob for these pt and so coming off those may improve and we have to be cautious about worsening these sx