10/19 Psychosis - Tobia Flashcards
psychosis
how to approach deciding if someone has psychosis
rule out life threatening causes:
- stat EKG
- vital signs
- consider withdrawal syndromes (esp from alcohol, sedative hypnotics)
then, make sure psychosis isnt caused by an underlying medical condition
which neurotransmitter is implicated in all psychoses
dopamine
Hibernotherapie
compound used by French anesthesiologist who noticed that using it allowed for significantly less anesthesia intraoperatively
- as a result: pts experienced drop in all-cause mortality
psychiatrist friend decided to try on psych patients to reduce agitation
- as a result: pt reported less agitation AND improvement of psychotic sx
FDA approved as clorpromazine
- hits DA receptors in CNS
- first antipsych!
role of dopamine in psychoses
final common pathway for all psychoses
- substance-induced (ex. stimulants)
- resulting from general medical condition
- deliriums
DA neuroanatomy
long tracts
short tracts
long tracts:
- nigrostratal tract
- mesolimbic tract
- mesocortical tract
short tracts:
- tubero-infundibular tract
- retina and adrenal medulla
nigrostriatal tract
fxs
cell bodies/projections
what does DA excess in this tract look like?
- synthesizes most of CNS dopamine
- influences fx of extrapyramidal motor system
- cell bodies found in substantia nigra pars compacta → project to D2 receptors in striatum (caudate and putamen)
dopaminergic excess in nigrostriatal tract
- neurocognitive deficits: speech, memory, attn/conc
- increase in DA in striatum thought to be related to neurocog deficits in schizophrenia
- movement disorders (hyper/brady/akinesis)
common side effect of antipsychotics and why?
Parkinsonism (hypokinetic movement disorders)
- psychosis is resulting from relative or absolute high level of DA in CNS
- antipsychotics reduce DA → drop DA that would hit inhibitory D2 receptors in the indirect pathway (basal ganglia) → overall bradykinetic
mesolimbic tract
cell bodies in VTA of midbrain → project to D4 receptors in limbic system
hyperactivity?
- positive sx of schizophrenia
mesocortical tract
cell bodies in VTA of midbrain → project to frontal cortex, cigulate and prefrontal gyri
hypoactivity via D2 receptor antagonism
- negative sx
- mood and cognition effects
schizophrenia and the DA shunt
conditions like schizophrenia have both positive and negative sx
- potentially explained by thinking of a “dopamine shunt” moving DA from mesocortical tract → mesolimbic tract
- hypoactivity in mesocortical tract → negative sx
- hyperactivity in mesolimbic tract → positive sx
tuberoinfundibular tract
links ___ & ___
function
effect of antipsychotics
TI tract (short pathway)
links hypothalamus → pituitary
- chronic DA secretion → decr prolactin secretion
- therefore…one side effect of medications that lower CNS DA concentration is: HYPERPROLACTINEMIA
common side effects of medications to decrease CNS DA
- reduction of positive sx (mesolimbic)
- aggravation of negative sx (mesocortical)
- hyperprolactinemia (TI tract)
retina DA
believed that excess DA here → visual hallucinations associated with psychosis
psychotic disorders
2 groups, disorders within them
schizophrenia spectrum
- brief psychotic disorder
- schizophreniform disorder
- schizophrenia (schizoaffective disorder)
other psychotic disorders
- delusional disorder
- catatonia
schizophrenia
two or more for a 1-month period
- positive sx
- delusions
- hallucinations
- disorganized speech
- disorganized or catatonic behavior
- negative sx
(formerly) Schneider’s First Rank sx
1. delusional perceptions (aka ideas of reference): thought or belief that is 1. not bound in reality and 2. fixed/rigid
- two-stage phenomenon consisting of a normal perception followed by a delusional interpretation
- special and highly personalized significance
2. somatic passivity → belief that:
- pt is a passive recipient of bodily sensations that are imposed from the outside
- affect, impulses, and/or motor activities are controlled by an outside force
3. thought insertion: belief that thoughts are put into mind by external force
4. thought withdrawal: belief that thoughts are being removed from mind by external force
5. thought broadcast: belief that thoughts are somehow transmitted to others
6. hallucinations: perceptual disturbances that have no environmental cue
7. illusions: misinterpretation in response to an environmental cue
negative sx of schizophrenia
5 A’s
- aPathy/avolition
- aLogia (poverty of speech/thought)
- Affective flattening
- aNhedonia/asociality (withdrawal)
- aTtention deficit
due to mesocirtical tract (DA hypoactivity → neg sx)
schizophrenia
social/occupational dysfx
6mo
exclusionary criteria:
- schizoaffective and mood disorder
- autism spectrum disorder
- substance/GMC
defense mech that best characterizes sx of schizophrenia
how do we distinguish between plain old personality disorder and psychosis (ex. schizophrenia)
projection
distinguish between personality disorder (ex. paranoid PD) and psychosis (ex. schizophrenia) by looking at frontal lobe fx
- loss of the protective override between 18-35 → psychosis
psychological determinants of schizophrenia
unconscious process through which individual attributes his/her unacceptable feelings, impulses or thoughts to another
- ego process
- characterized by impaired frontal lobe fx
social determinants of schizophrenia
myths and accepted social theories
myths
- schizophrenogenic mom
- double bind (family dynamic theory that said individ gets two opposing messages from same communication)
accepted social theories
- downward drift: schizophrenia causes poverty
- stress-diathesis model: genetic/biological factors can predispose but psych/social factors are precipitants
- i.e. anyone can be made psychotic with enough psych/social stressors…the level req is determined by genetic predisp
schizophreniform disorder
schizophrenia that lasts between 1-6 months
past 6mo → schizophrenia
brief psychotic disorder
ONE or more schizophrenia sx for 1-mo
- NOT INCLUDING NEGATIVE SX
duration: 1day-1mo
recovery: full return to premorbid fx
usually precipitated by a stressor:
- witness to catastrophic event
- childbirth → postpartum onset
how do you determine if BPD or early schizophrenia?
presence of negative sx will point towards schizophrenia!
