Psychiatry - Psychosis Flashcards
What is psychosis?
People lose touch with reality, experiencing hallucinations and delusions
What is a hallucination?
A perception in the absence of a stimulus ie. hearing, seeing, smelling touching or tasting something that isn’t there.
What is a delusion?
A fixed false belief held despite rational argument or evidence to the contrary. It cannot be explained by the patient’s cultural, religious or educational background.
What is the lifetime risk of developing schizophrenia?
1%
What is the typical age of onset of schizophrenia in men and women?
Men 20-30
Women 50-60
Which gender is effected more by schizophrenia?
Both equal
Age of onset of schizophrenia generally?
Second to third decade
But another peak in fourth-fifth
Lifetime risk of developing schizophrenia in first degree relatives of people with schizophrenia?
10%
Aetiology of schizophrenia? (Give 5)
- Genetics
- Obstetric complications e.g. pre-eclampsia, low birth weight, emergency C section, pre-natal malnutrition
- Substance misuse
- Social disadvantage
- Urban life and death
- Migration
- Ethnicity - Black Carribbean and African
- Expressed emotion - highly critical or overly involved relatives
- Premorbid personality - schizotypal disorder
- Adverse life experience- sexual or physical abuse
Give 4 examples of illicit substances that can cause psychotic symptoms
- Cannabis
- Amphetamines
- Cocaine
- LSD
Why does the risk that smoking cannabis has on developing schizophrenia vary from person to person?
`COMT (catechol-O-methyl transferase) breaks down dopamine.
COMT is coded for by 2 alleles Val and Met
The Val allele increases the risk of schizophrenia in cannabis users. So those who are Val-Val are at highest risk.
Also the type of cannabis smoked contains different concentrations of tetrahydrocannabinol - e.g. skunk is dangerous
What are the main three theories surrounding the development of schizophrenia?
- Neurodevelopmental
- Neurotransmitter
- Psychological
What is the evidence for the neurotransmitter theory of schizophrenia? (The dopamine hypothesis - that positive symptoms occur as a result of dopamine overactivity in the mesolimbic tracts and negative symptoms occur due to underactivity of dopamine in the mesocortical tracts)
- All known antipsychotics are dopamine antagonists (receptor blockers)
- Antipsychotics work better against positive rather than negative symptoms
- Dopaminergic agents e.g. amphetamine, cocaine can all induce psychosis.
What are antipsychotics?
Dopamine antagonists
What are the three clinical phases of schizophrenia?
- At risk mental state (ARM)
- Acute phase - positive symptoms
- Chronic phase - negative symptoms
Generally, how much shorter life-span does a person with schizophrenia have, when compared to the general population?
25 years
On what receptor do antipsychotics work?
Dopamine (D2) receptor
What are Schneider’s first rank symptoms?
- Delusional perception
- Passivity phenomena
- Third person auditory hallucinations
- Thought alienation (interference)
How many first rank and secondary symptoms are required to diagnose schizophrenia?
First rank = More than one
Secondary = 2 or more
Give 6 secondary symptoms of schizophrenia?
- Delusions
- 2nd person auditory hallucinations
- Hallucinations in any other modality
- Thought disorder
- Catatonic behaviour
- Negative symptoms
Give 3 examples of negative symptoms
- Blunting of affect
- Amotivation (Avolition)
- Poverty of Speech
- Poverty of Thought
- Self-neglect
- Lack of insight
- Poor non-verbal communication
- Deterioration in functioning
- Loss of interest (anhedonia)
Give 5 types of delusion
- Thought interference (alienation)
- Grandiose
- Passivity
- Delusional perception
- Delusions of reference
- Nihilistic
- Persecutory
What are the three forms of thought interference?
- Thought insertion
- Thought withdrawal
- Thought broadcasting
Give 5 examples of positive symptoms
- Hallucinations
- Delusions
- Passivity phenomena
- Thought alienation
- Lack of insight
- Disturbance in mood
- Catatonic behaviour
What is a delusional perception?
A true perception to which an individual attributes a false perception
How long do positive symptoms have to be present before diagnosing schizophrenia?
1 month
Including prodrome and chronic phase - 6 months
Give 6 different forms of psychoses
- Schizophrenia
- Delusional disorder
- Schizotypal disorder
- Depressive psychosis
- Manic psychosis
- Organic psychosis
What is the drug used to treat refractory schizophrenia?
Clozapine
What is the definition of refractory schizophrenia? Ie. when would you prescribe clozapine?
Failure to respond to 2 or more antipsychotics at least one of which is an atypical when given at the therapeutic dose for at least 6 weeks
What is the main (serious) side effect of clozapine?
Agranulocytosis in 0.7%
Weekly blood tests must be conducted on patients starting on the drug as 3% become neutropenic
Give three examples of a typical antipsychotic
Chlorpromazine, haloperidol, flupentixol decanoate
Give three examples of an atypical antipsychotic
Olanzapine, risperidone, quetiapine, aripiprazole, clozapine
What is the other name for first generation and second generation antipsychotics?
First generation - typical
Second generation - atypical
Give the advantages and disadvantages of typical (first generation) antipsychotics
Advantage - cheap, effective and can be used as a depo
Disadvantage - cause EPSE’s! can increase prolactin levels
Give the advantages and disadvantages of atypical (second generation) antipsychotics
Advantage - don’t cause EPSE’s, don’t increase prolactin levels
Disadvantage - can’t be used as depo, more expensive
Which of the second generation antipsychotics can increase prolactin levels?
Risperidone
How to second generation antipsychotics work?
Block dopamine and serotonin 5-HT2 receptors
What type of antipsychotic is clozapine?
Atypical (weak dopamine antagonist)
What are the 4 EPSE’s associated with typical antipsychotic use?
- Dystonia - sustained involuntary muscle spasm
- Akithisia - subjective feeling of restlessness
- Tardive dyskinesia - rhythmic involuntary movements of mouth, face, limbs and trunk (grimace/chew)
- Parkinsonism - resting tremor, rigidity, bradykinesia +/- mask like facies and shuffling gait
How do you treat dystonia secondary to antipsychotic use?
Anticholinergic e.g. procyclidine
How do you treat akithisia?
Decrease dose or change of antipsychotic
+/- benzo +/- propanolol
How do you treat tardive dyskinesia?
Switch to atypical
AVOID anticholinergic
(Note/ this can be irreversible)
How to treat parkinsonism?
Anticholinergic (procyclidine)
Give 5 side effects of antipsychotics
- Anticholinergic side effects - tachycardia, dry mouth, blurred vision, constipation, urinary retention
- Seizures
- Arrhythmias
- Weight gain (olanzapine and clozapine)
- Hyperprolactinaemia - galactorrhoea, amenorrhoea, gynaecomastia, hypogonadism
- Sedation
- EPSEs
- Increased risk of diabetes
- Neuroleptic malignant syndrome
Which two antipsychotics typically cause weight gain?
Clozapine and olanzapine
What is often the trigger for neuroleptic malignant syndrome (NMS)?
New antipsychotic or increased dose
What is neuroleptic malignant syndrome and give 3 clinical features?
NMS = A life threatening reaction to antipsychotic drugs that is typically related to fever, altered consciousness, muscle stiffness and rigidity, and disturbance of the autonomic nervous system (tachycardia, labile BP)
What is the management of neuroleptic malignant syndrome?
- Stop antipsychotic
2. Get urgent medical treatment
What investigation and results would you see in NMS?
- Increased CK
2. Increased WCC
What is the most serious consequence of NMS?
Death from acute renal failure secondary to skeletal muscle breakdown
