Schizophrenia + Psychosis Flashcards
what is schizophrenia
mental disorder characterised by abnormal social behaviour and failure to understand reality
brain abnormalities in schizophrenia
ventricular enlargement
reduced frontal lobe + grey matter volume
disorganised cytoarchitecture in the hippocampus
why is there loss of grey matter in schizophrenia
reduced synapses NOT less neurones
risk factors for schizophrenia
80% heritability daily cannabis use 50% increased risk if viral CNS infection in childhood pre-eclampsia foetal hypoxia
what are schneider’s first rank symptoms in schizophrenia
delusional perception thought withdrawal/ insertion/ broadcasting auditory hallucinations somatic hallucinations passivity phenomena
what is passivity phenomena
feelings or actions controlled by ‘external agency’ delusions
what are somatic hallucinations
perception of physical experience occurring in the body
what is important to ask about auditory hallucinations
2nd person - 'you' 3rd person - 'they' 'he/she' how many voices? what do they say?- running commentary/ discussing the patient/ internal dialogue? commands? compelled to act on commands?
what is a delusion
a fixed, false belief not based on evidence or fact
types of delusions in schizophrenia
grandoise
paranoid
bizarre
two types of schizophrenia by symptoms
postitive
negative
positive symptoms
delusions
hallucinations
thought disorder
negative symptoms
apathy
lack of motivation
social withdrawal
cognitive impairment
disorders of thought
thought insertion/ withdrawal/ broadcasting
knights move thinking
flight of ideas
tangential thinking
flight of ideas
jumping from one topic to the next with loose connections between concepts
knights move thinking
a complete loosening of associations where there is no logical link between one idea and the next
tangential thinking
wandering from the topic and never returning to it or providing the information when requested
what is catatonia (often seen before introduction of antipsychotic drugs)
state of increased tone in muscles at rest
stupor (unresponsiveness)
hyperactivity
mutism (no speech)
by what mechanism is psychosis thought to be induced
overactivity of dopamine in mesocorticgl and mesolimbic systems
what drugs can induce psychosis
apomorphine - D2 receptor agonist
amphetamine - releases dopamine into the brain
causes of psychosis
schizophrenia mania depression delirium dementia psychoactive substance use
definition of psychosis
delusions + hallucinations
- inability to distinguish between experience and reality
- loss of insight
what are self referential experiences
the belief that external events are related to oneself
e.g. TV is transmitting messages to me
what does the presence of psychosis in depression indicate
very severe depression
psychotic symptoms seen in depression
delusions of worthlessness/guilt
hallucinations of accusing/ insulting / threatening voices- typically 2nd person “its your fault”
psychotic symptoms seen in mania
grandoise delusions- special ability / religiosity
auditory hallucinations e.g. god’s voice
flight of ideas
schizoaffective disorder
schizophrenia + bipolar disorder
characteristic of schizoaffective disorder
presence of symptoms typical of schizophrenia + affect disorder
- episodes of either shizo-mania or schizo-depressed
what is delirium
acute confusion with transient global disturbance
potential causes of delirium
alcohol withdrawal infection/ septicaemia hypoglycaemia space occupying lesion encephalitis drug intoxication/ withdrawal post operation hypoxia
signs/symptoms of delirium
clouding of consciousness
- ranges from subtle drowsiness to unresponsiveness
- disorientation in time, place, person
- fluctuating severity
- worse at night
impaired concentration/ memory visual- hallucinations / illusions irritability insomnia threatening auditory hallucinations agitation
function of D1 receptor
stimulates cAMP
function of D2 receptor
inhibits adenylyl cyclase
inhibits voltage activated calcium channels
opens potassium channels
which receptor to typical anti psychotics block
D2
why are atypical antipsychotics preferred
less likely to cause extra-pyramidal side effects
better at treating negative schizophrenia symptoms
why do antipsycotics cause hyperprolactin
block D2 receptors in tuberoinfundibulnar system
antipsycotics block histamine receptors, what effects does this cause
increased appetite
sedation
anti-psychotics block alpha adrenergic receptors, what effect does this cause
postural hypotension
