12. Psychosis

Question 1

what is psychosis?

Answer 1

a set of symptoms - not a diagnosis

presence of hallucinations and delusions

Question 2

define hallucinations

Answer 2

a perception without an acompanying stimulus

in any sensory modality

Question 3

how can hallucinations be caused by organic pathologies?

Answer 3

if visual hallucinations - can be due to tumour or eye disease

Question 4

what hallucinations are designed as physiological?

Answer 4

hypnogogic - when going to sleep

hypnopompic - upon waking

Question 5

define delusions

Answer 5

a fixed, false belief which is unshakeable, outside of cultural norms

Question 6

what are some common misconceptions of schizophrenia?

Answer 6

• not a split mind

- patient is more dangerous (only 5% of violent crimes commited by those with severe mental illness)

Question 7

what are some clinical features of schizophrenia?

Answer 7

first rank symptoms - hearing thoughts aloud, running commentary, third person delusions
passivity experiences - belief that an action or feeling is caused by external force
thought withdrawal - belief thoughts are being taken out of the mind
thought broadcast - belief that everyone knows what the patient is thinking
though insertion - belief that thoughts are being implanted by others
delusional perceptions - attribution of a new meaning to a normally percieved object
somatic hallucinations - feeling like they are being touched

Question 8

how can symptoms of schizophrenia be classified?

Answer 8

positive (adding something) - delusions, hallucinations, thought disorder, lack of insight
negative (taken away) - underactivity, low motivation, social withdrawal, emotional flattening, self neglect

Question 9

rummarise the pathophysiology of schizeophrenia

Answer 9

dopamine levels, evidence:
drugs that increase dopamine levels(eg: amphetamine) induce psychosis
drugs that antagonise dopamine treat psychosis (D2 especially)

Question 10

what are some brain changes tht occur in schizoprhrenia?

Answer 10

enlarged ventricles
decreased grey matter
decreased temporal lobe vol
reduced size of limbic structures and prefrontal cortex
changes at synapses
fewer oligodentrocytes
fewer thalamic neruones

Question 11

what other features might schizophrenics show?

Answer 11

movement disorders - role of basal ganglia

Question 12

how is schizophrenia treated?

Answer 12

antipsychotics - block D2 receptors throughout the CNS, inhibited in mesolimbic and mesocortical pathways
atypical antipsychotics - lower affinity for D2 receptors so milder side effects, also block 5HT2 receptors (so some action on serotonin systems)

Question 13

how do side effects of antipsychotics come about?

Answer 13

blocks other pathways such as nigrostriatal - affects movement, causing parkinson like symptoms
dopamine inhibits prolactin, so amenorrhoea, galactorrhoea, decreased fertility, libido and osteoporosis

Question 14

if schizophrenia is left untrated what may develop?

Answer 14

catatonia - due to involvement of GABA

Question 15

wghat are some challenges in treating shizophrenia?

Answer 15

patients do not think they are ill - lack insight so can affect compliance with treatment so medication can be given via depot injection

Question 16

what is hte prognosis of schizophrenia?

Answer 16

if treatment started early then good outlook, 50% do well long term
especially with no family history, good premorbid function, acute onset, mood disturbance, prompt treatment, maintenance of motivation

Question 17

what are the ;long term complications of schizophrenia?

Answer 17

cause mortality twice as high as general population
shorter life expectancy
higher incidence of CVS, resp and cancer
9x greater suicide
2x greater risk of violent death 
substance misuse more common
many patients smoke