Psychosis Flashcards
What is the definition of psychosis?
The presence of hallucinations or delusions
Describes symptoms - not a diagnosis in itself
What are hallucinations?
Perception without stimulus
can be any sensory modality
Visual hallucinations are usually organic (problem with brain or eyes), auditory hallucinations very common in psychosis
What are the 2 types of hallucination experienced by ‘normal’ population?
Hypnogogic - when going to sleep
Hypnopompic - on waking up
What are delusions?
A false belief which is unshakable and outside of cultural norms
e.g. religion is not a delusion
What are the first rank symptoms seen in patients with schiziphrenia?
- Auditory hallucinations
- Passivity experiences
- Though withdrawl, broadcase or insertion
- Delusional perceptions
- Somatic hallucinations
What are the different forms of auditory hallucination?
Thought echo: hearing thoughts aloud
Running commentary: on what the patient is doing e.g . ‘He is brushing his teeth’
Third person: voices talking amounst themselves or talking directly to the patient
What are passivity experiences experiencesd in schizophrenia?
The patient believes an action or feeling is caused by an external force
e.g. ‘MI5 have been moving my leg’
Can be a very frightening feeling
What is thought withdrawl, broadcast or insertion?
- Thought withdrawl - thoughts are being taken out of the mind
- Thought broadcast - everyone knows what the person is thinking
- Though insertion - you think the thought has been implanted by others
What is delusion perception?
Where the patient attributes a new meaning to a usually normally percieved object.
E.g. The traffic light going red means aliens are going to land soon
What are somatic hallucinations?
Patients can feel things ‘inside’ their body e.g. feel their internal organs moving
What is the difference between positive and negative hallucinations experienced by someon with schizophrenia?
Positive symptoms: symptoms gained
- delusions
- hallucinaions
- thought disorders
- lack of insight
Negative symptoms: thinks that take away from the patients
- underactivity
- low motivation
- social withdrawl
- emotional flattening (don’t engage emotionally with people)
Explain the dopamine theory of schizophrenia
Drugs that cause the release of dopamine induce psychotic symptoms
All medications that antagonise DA receptors help treat psychosis. The strongest affinity being D2 receptors
What are the 4 dopamine pathways in the brain?
Mesocortical: thought to be underactive in schizophrenia (responsible for negative symptoms)
Mesolimbic: thought to be overactive in schizophrenia
Nigrostriatal
Tuberinfundibular
What brain changes are seen in a schizophrenic brain?
- Enlarged ventricles
- Reduced grey matter (reduced brain weight)
- Decreased temporal lobe volume (thought to be why auditory hallucinations occur)
- Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex
What brain changes have lead to the aberrant connectivity theory of schizophrenia?
- Decreased pre-synaptic markers
- Decreased oligodendroglia
- Fewer thalamic neurones
How do typical antipyschotics treat schizophrenia?
Dopamine antagonists
- Block D2 receptors in all CNA dopaminergic pathways
- Mainly act on mesolimbic and mesocrotical pathways but side effects come from antagonising D2 receptors in other pathways
- can get Parkinson like symptoms
How do atypical antipsychotics work?
- Lower affinity for D2 receptors
- Milder side effects as rapidly dissociated from D2 receptor
- Block 5HT2 receptors
- Can cause impaired glucose tolerance, weight gain and prolonged QT
Where in the brain are D2 receptors mainly located?
- Striatum
- Substantia nigra
- Pituitary gland
What is catatonia? (Develops in patients treated with dopamine for schizophrenia- rarer now than it used to be)
More than 2 weeks, one or more of abnormal movement:
- Stupor/ mutism
- Excitement
- Posturing
- Negativism
- Rigidity
- Waxy flexibility
- Command Automatism
Though to be due to less GABA binding so loss of inhibitory effect
What are some of the side effects of antipsychotics that antagonise Dopamine, and why?
Dopamine normally inhibits prolactin release from pituitary. DA antagonists recude dopamines inhibitory functions, therefore leading to increased prolactin levels
Can lead to:
- Amenorrhoea
- Galactorrhoea
- Decreased fertility
- Reduced libido
- Long term can cause osteopenia/ osteoporosis
What are some of the difficulties in treating a schizophrenic patient?
- They lack insight - don’t believe they’re unweel so hard to convince to treat
- Medications therefore not taken (especially if they believe the Dr is part of their hallucinations)
- Medications can be given as short acting IM but this means may need pinning down several times a day, or given as depot injection
What are some good prognostic factors for treating someone with schizophrenia?
- No family history
- Good premorbid function
- Acute onset
- Mood disturbance
- Prompt treatment
- Maintenance of therapy
What is the prognosis of patients with schizophrenia?
- Mortality x2 as hight than general population
- Shorter life expectancy
- Incidence of CVS, respitory disease and cancer is higher
- Suicide risk is x9 higher than the general population
- Death from violent incidences x2 as high
- 50% have a substance misuse problem
- Higher rate of smoking
