Schizophrenia Flashcards
What is schizophrenia?
A mental illness which occurs when the parts of the brain responsible for emotion and sensation stop working properly
Psychotic episodes form part of schizophrenia.
What are the 8 disturbances of schizophrenia?
Characterized by disturbances in:
- thinking (delusions)
- perception (hallucinations)
- self-experience (feelings/thoughts are under external control),
- cognition (impaired attention)
- volition (loss of motivation)
- affect (blunted emotional expression)
- behaviour (inappropriate, bizarre responses)
- Psychomotor disturbances (catatonia)
- Symptoms must have persisted for at least one month and not a manifestation of another health condition and not due to the effect of a substance or medication.
What are the three aims of schizophrenia treatment?
Remission (symptoms resolved)
Relapse prevention
Restore function
What is the mental health act?
Individuals can be sectioned, detained and treated against their will
Treatment can be given without consent using proportionate force if necessary
Relatively recently, community treatment orders (CTOs) have also been introduced
What are the NICE guidelines around prescribing antipsychotics?
Must offer people a choice of antipsychotic
Asking people which side-effects they are most willing to put up with
Conventional wisdom: all equally effective (apart from clozapine)
Typical versus atypical
Higher risk of movement disorders versus higher risk of metabolic disorders
Guidelines say don’t combine unless swapping from one to another or augmenting clozapine
Treatment with an antipsychotic is an individual therapeutic trial
Monitor symptoms
Monitor adverse effects
What is Neuroleptic Malignant Syndrome (NMS)?
Fever
Encephalopathy (altered mental state)
Vital signs dysregulation (autonomic instability)
Enzyme elevation (creatine kinase)
Rigidity of muscles
Typical antipsychotics
What are long-acting injectable antipsychotics?
In the UK, about 30% of patients with schizophrenia are prescribed antipsychotic long-acting injections (LAIs)
LAIs may have a place at various stages in care and they should be one of the options discussed with any patient requiring long-term treatment, even early in the illness course
What is Clozapine?
The first atypical
Very different receptor binding profile from other antipsychotics
Extensive histamine and muscarinic block as well as 5-HT2A and 5-HT2C
Effective when other antipsychotics fail
But risk of serious blood disorders as well as other serious side effects so only used under strict monitoring conditions
The use of clozapine is restricted to people with ‘treatment resistant’ schizophrenia because of the need for regular blood monitoring due to the risk of blood dyscrasias.
What is the evidence surrounding long-term use of antipsychotics?
Lots of evidence for short-term effectiveness
Schizophrenia is a disorder characterized by acute episodes
Most guidelines recommend at least 1‐2 years of antipsychotic treatment
Of those discontinuing antipsychotic treatment, up to 75% have a relapse within 12 to 18 months.
The effects of antipsychotic treatment beyond the first 2 years of treatment are not understood
What are the reductions in life expectancy associated with mental illness?
7-11 years for a single depressive episode or recurrent depressive disorder
9-20 years for bipolar disorder
9-24 years for substance use
10-20 years for schizophrenia
13-22 years for personality disorders
8-10 years for heavy smoking
Why is there reduced life expectancy for those with mental illnesses?
- Perceived deficits in understanding and motivation
- Less likelihood to discuss physical health problems
- Misguided beliefs by professionals about ability to change
- Dismissal of physical symptoms
- Unequipped teams
- Lack of consensus as to where care should be provided
- Reluctance to change drugs despite metabolic adverse effects
What is psychosis?
Hallucinations
Sight, sound, smell, touch, taste
Delusions
Eg. persecutory, grandiose, lack of self-awareness
Confused and disturbed thoughts
Eg. rapid and constant speech, disturbed speech, loss of train of thought
What are the 7 causes of psychosis?
- Alzheimer’s, Parkinson’s, Huntington’s diseases
- Depression, bipolar disorder
- Some types of epilepsy
- Stress, trauma
- Lack of sleep
- Drugs
- Schizophrenia
What are the 5 positive symptoms of schizophrenia?
Increase in abnormal behaviours
Hallucinations
Delusions
Disordered thoughts
Disturbed speech
What are the 7 negative symtoms of schizophrenia?
Absence of normal active behaviours
Affective blunting
Avolition
Anhedonia
Poverty of speech
Social withdrawal
Neglect of hygiene
What are the 5 cognitive symptoms of schizophrenia?
Disturbance of of normal thought processes
Poor executive function
Poor decision making
Memory problems
Attention deficits
What are the 3 causes of schizophrenia?
Genetic - strongly inherited – 50% in monozygotic twins but no specific gene identified
Environmental
no specific factors implicated
pregnancy and delivery complications
prenatal and childhood virus infection
urban birth and residence
Psychosocial factors (dysfunctional family environment)
What are the dopamine pathways associated with schizophrenia?
Overactive mesolimbic pathway (positive symptoms)
Underactive mesocortical pathway (negative symptoms)
Nigrostriatal pathway (extrapyramidal effects)
D2 receptor gene polymorphism risk factor in schizophrenia
Antipsychotics are all D2 receptor antagonists
What are typical/first generation antipsychotics?
High affinity D2-receptor antagonists eg. chlorpromazine, haloperidol
Effective ONLY against positive symptoms
What are the 5 side effects of first gen/typical antipsychotics?
Worsened negative symptoms
‘Extrapyramidal’ side effects: acute dystonias (Parkinson’s like), tardive dyskinesia (Huntington’s like)
Increased prolactin release – ‘galactorrhea’
Blurred vision, dry mouth, constipation
Sexual dysfunction
What are atypical/second gen antipsychotics?
Lower affinity D2 antagonists and high affinity 5HT2 receptor antagonists, which has better control over levels of dopamine and serotonin
eg. Clozapine, olanzapine, risperidone, aripiprazole
Effective against both positive and negative symptoms
Less side effects than ‘typical’ antipsychotics, especially motor effects.
Clozapine only given if >2 other antipsychotics are ineffective
What are the side effects of atypical receptor antagonists?
Weight gain
Diabetes
Agranulocytosis…. leukopenia (especially clozapine)
Sedation
Hypotension
Why use serotonin 2A receptors in schizophrenia?
Problems with selective D2 receptor antagonists
Serious dopaminergic-related side effects
Only control positive symptoms
5HT2 receptor agonists can cause psychotic episodes (eg. LSD)
How are glutamate receptors associated with schizophrenia?
Excessive glutamate release and disfunctional receptors
Blocking NMDA receptors can cause psychosis
How are nicotinic acetylcholine receptors associated with schizophrenia?
Shown to be abnormal in schizophrenics
High proportion of people with schizophrenia smoke/vape
Nicotinic receptor activation can enhance attention, memory, ‘sensory gating’ but tobacco smoke induces CYP1A2 activity which metabolises some APDs
How are muscarinic acetylcholine receptors associated with schizophrenia?
Can modulate glutamate and dopamine release in the striatum
Activating these can control all symptoms
