Pyschotic Disorders Flashcards
Define psychosis
The presence of hallucinations or delusions
What are hallucinations?
Perception without a stimulus
What are visual hallucinations usually caused by?
Problems with brain or eye
(Not psychotic)
What are hypnogogic hallucinations?
as you’re going to sleep
What are hypnopompic hallucinations?
As you’re waking up
What is a delusion
A fixed false belief which is unshakeable
Outside of cultural norms
What are the 5 first rank symptoms of schizophrenia?
- auditory hallucinations
- passivity experiences
- thought withdrawal, broadcast or insertion
- delusional perceptions
- somatic hallucinations
Types of auditory hallucinations
- running commentary
- thought echo: hearing thoughts aloud
- third person: voices referring patient to 3rd person
What are passivity experiences?
Patient believes an action or feeling is caused by an external force
e.g. MI5 have been moving my leg
What is thought withdrawl?
Feeling like their thoughts are being taken out of their mind
What is thought broadcast?
Feeling like everyone knows what the person is thinking
What is thought insertion?
Feeling that thoughts are implanted by others
Experiencing one’s own thoughts as someone else’s
What is delusional perception?
Attribution of new meaning, usually in sense of self reference to normally perceived object + cannot be understood as arising from patient’s affective state
seeing something that has actually happened by interpreting in a delusional way
What are somatic hallucinations?
Mimics feeling from inside the body
e.g. feeling snake inside body, feeling heart twisting inside of them
Positive symptoms of schizophrenia
something added
- delusions
- hallucinations
- thought disorder
- lack of insight
Negative symptoms of schizophrenia
something taken away
- underactivity
- low motivation
- social withdrawal
- emotional flattening
- self neglect
What is thought disorder
Problem with organisation of thoughts in logical way
What is lack of insight?
Patient doesn’t realise that they are unwell
Positive vs negative symptoms of schizophrenia
- positive: something added
- negative: something taken away
Evidence for involvement of dopamine in schizophrenia
- drugs than increase dopamine levels induced by psychosis
- drugs that antagonise dopamine (especially at D2 receptor) treat psychosis
Where is the mesolimbic pathway between?
From Ventral temgental area
To Limbic structures + nucleus accumbens
What is the mesocortical pathway between?
From ventral tegmental area
To frontal + cingulate cortex
Mesolimbic pathway involvement in schizophrenia
Overactive in schizophrenia
Causes positive symptoms
Mesocortical pathway involvement in schizophrenia
Underactive in schizophrenia
Causes negative symptoms
Brain changes in schizophrenia
- enlarged ventricles
- reduced grey matter (brain weight)
- decreased temporal lobe volume
- reduced hippcampal formation, amygdala, parahippocampal gyrus + prefrontal cortex
Neuropathology of schizophrenia
- decreased pre synaptic markers
- decreased olgiodendroglia
- fewer thalamic neurones
- these three changes have lead to aberrant connectivity theory
Treatment of schizophrenia
- typical antipsychotics: block D2 receptor in all 4 CNS dopaminergic pathways
- atypical antipsychotics: lower affinity for D2 receptors + block 5HT2 receptors
Why do atypical antipsychotics have milder side effects than typical?
Atypical dissociate rapidly from D2 receptors
Side effects of atypical antipsychotics
- hyperprolactinaemia
- movement affected
- amenorrhoea
- galactorrhoea
- decreased fertility + libido
- osteoporosis
- erectile dysfunction
What are the 4 CNS dopaminergic pathways
Mesolimbic pathways
Mesocortical pathways
Nigrostriatal pathway
Tuberoinfundibular pathway
What are side effects of antipsychotics due to?
Blockage of dopamine receptors in other pathways
What is the nigrostriatal pathway between?
From substantia nigra pars compacta
To striatum
What does use of antipsychotics on the nigrostriatal pathway cause?
Less dopamine = less movement
What makes up the striatum?
Caudate nucleus
Putamen
What is the tuberoinfundibular pathway between?
From arcuate + periventricular nuceli of hypothalamus
To infundibular region of hypothalamus
Why is hyperprolactinaemia a side effect of antipsychotics?
- dopamine inhibits prolactin release from anterior pituitary
- DA antagonists lower DA > loss of inhibition of prolactin
- prolactin levels increase
What can hyperprolactinaemia cause?
- amenorrhoea
- galactorrheoa
- decreased fertility
- reduced libido
- erectile dysfunction
- osteopenia/osteoporosis
Difficulty in treating people with schizophrenia
- patients can have a lack of insight
- they don’t believe that they are unwell
- medications are often not taken
Good prognositic factors of schizophrenia
- absence of family history
- good premorbid function
- acute onset
- mood disturbance
- prompt treatment
- maintenance of initiative + motivation
Long term complications of schizophrenia
- shorter life expectancy
- higher incidence of cardiovascular, respiratory disease + cancer
- greater suicide risk
- risk of violent death
- smoking
- substance misuse
How can difficulties of treating schizophrenia be overcome?
Medications can be given via depot injection
