3.3 - Schizophrenia & Psychosis Flashcards
1
Q
How is psychosis (madness) seen differently to other mental illnesses like depression, anxiety etc?
A
- people who hear voices/disorganised behaviour/thought disorders are considered differently to other mental illnesses
- seen as less relatable and put in a separate box
2
Q
What are the different diseases which can cause ‘madness’?
A
- schizophrenia - ‘true psychosis’
- mania, depression, schizoaffective disorder, puerperal psychosis (linked with giving birth)
- delirium - acute brain failure = clouding of consciousness, attention deficit
- encephalopathy, acquired brain injury, stroke
- dementia - Alzheimer’s, vascular, LBD/Parkinson’s, Huntington’s
- personality disorders - parapsychotic phenomena (e.g. someone who was abused perhaps hears voice of abuser), PTSD
- drugs - cocaine, LSD, cannabis, alcohol, L-dopa, steroid, anticholinergics
- metabolic - Ca2+, Mg2+, vitamin B12
- endocrine - thyroid, Cushing’s, Addison’s
- infections - encephalitis, syphilis
3
Q
What is psychosis?
A
- a group of pathologies which disrupt the process of perceiving and interpreting reality
- typically made up of hallucinations, delusions and/or thought disorder
- brain is not able to process what is happening in reality so they are experiencing everything much differently to us
- can be conceptualised as reality failure
4
Q
What is consciousness?
A
- consciousness is probably modular, not unitary
- parallel processing - battery of unconscious processes
- content of conscious awareness is selected by attention - both active/voluntary, and passive (salience and automatic screening of irrelevant stimuli)
5
Q
What are auditory verbal hallucinations?
A
- thoughts/internal monologue experienced as external/other
- experienced by 5% of healthy population
6
Q
What are delusions?
A
- fixed, false, unshakeable belief, out of context with cultural background
- always have to be interpreted with current social and cultural contexts
- could be result of efforts to make sense of perplexity - the brain doing a ‘doxastic shear-pin’ where it allows continued function in the face of paralysing difficulty by only shutting down one part of itself and letting the rest function
- e.g. someone forgets to put food in the fridge, eat it later and it has gone off so they think their neighbour is trying to poison them
- often persecutory - default to fear in the face of uncertainty to try to preserve life
- belief formation driven by intense feelings of being controlled/persecuted/culpable etc
7
Q
What are some positive symptoms of schizophrenia?
A
- those that add on to normal human experience and for schizophrenia include:
- hallucinations
- delusions - can be persecutory/grandiose, delusional perceptions, delusions of control (that you’re being controlled by someone), thought delusions or interference (thoughts don’t feel like your own)
8
Q
What are some negative symptoms of schizophrenia?
A
- those that are missing from the normal human experience and include:
- anhedonia - loss of enjoyment
- apathy - lose interest and motivation
- social withdrawal
- blunted mood
9
Q
What are some disorganised symptoms of schizophrenia?
A
- thought disorder
- disorganised speech/behaviour
- inappropriate affect - incongruence of mood and what they are saying
10
Q
How does schizophrenia affect one’s self awareness and experience?
A
Perplexity
- disruption of language/meaning
- aberrantly salient experiences
- overwhelmed by formless sense of something fishy going on
Disruption of the sense of self
- your thoughts/experiences lose their ‘mine-ness’
- your internal world (mind/body) spills into external world
- the ‘other’ intrudes into your internal world - the boundary between yourself and other’s experiences blurs
11
Q
What are the neurobiological mechanisms behind schizophrenia?
A
- significant genetic component - prevalence 1% and heritability 80%
- heritability from a single parent 10%, both parents 50%, 40% in MZ twins
- > 200 genes linked to schizophrenia - many epigenetic causes and few single gene causes
- mainly the genes for dopamine 2, neurodevelopment and inflammation
- excess of striatal dopamine (seen in PET scans) - especially in response to stress
- abnormal organisation of Default Mode Network - stimulus-dependent thought and self-reflection
12
Q
What is the role of dopamine?
A
- anticipated reward –> directed attention
- reward prediction error signalling
- salience (sense of importance attached to perceptions)
13
Q
What is working memory?
A
- preconscious working memory stores large amount of data
- allows you to contextualise the present moment
- deficits in working memory –> thought and perception loses context, flow, order?
14
Q
What are the causes of psychosis?
A
- genetic component - genes predisposing to schizophrenia must also confer significant advantage e.g. more flexible grasp of reality so you can fill in the gaps and link things together but extreme version with crazy conclusions
- developmental adversity/abuse - biased cognitive schemas, sensitised striatal dopaminergic system, high expressed emotion, ‘double-bind’ family dynamic
- neurodevelopmental - prematurity, hypoxia, infection, winter/spring births
- life stressors - stress-vulnerability model
- relationship with recreational drugs - cause 25% of psychosis, strong correlation with earlier age of cannabis use and strength of cannabis with onset of psychosis
15
Q
How do you treat psychosis?
A
- psychosis is a biopsychosocial illness and so is the treatment
- antipsychotics - antidopaminergic (also serotonergic, anticholinergic, antihistaminergic) - typical and atypical types that work on different receptors to different degrees
- psychological therapies - CBT for psychosis, avatar therapy (character made for patient that doctor talks with, just real enough to be immersive), helps patient get sense of agency over voices
- social support - supportive environments, structures and routines; housing and benefits; support with budgeting/employment
