Psychosis Flashcards
Incidence of schizophrenia
Life time incidence: 1%, typical onset 15-45 (18-25 commonly)
Overall risk is even for men and women, but men are affected earlier and more severely
Schizophrenia
A psychotic illness where there is a loss of contact with reality (hallucinations and delusions) and a disordering of thought
Aetiology of schizophrenia
Genetic
Obstetric factors
Substance misuse
Lifestyle factors
Genetic factors in schizophrenia
10x increased for 1st degree relatives, 48% risk if both parents have schiz
MZ twin concordance is 40-50%, DZ twin 10-20%
Rarely single genes may cause (DISC1/2)
Likely multiple risk genes overlapping with other mental illnesses
Obstetric factors in schizophrenia
Maternal malnutrition and illness during pregnancy, particularly 2nd trimester increase risk -> viral infections, pre-eclampsia, low birth weight, emergency C section
Schiz is more likely in people born in winter months
Substance misuse in schiz
LSD, amphetamines, cocaine and cannabis all produce psychotic states
Cannabis increases risk in people with the valine allele of the COMT enzyme
Greatest vulnerability is as a teenager, and it shows a doses response with amount/strength smoked
Socioeconomic factors in schizophrenia risk
Higher prevalence of schiz in lower SES adults which isn’t true for status at birth, indicating downward social drift
Prevalence is also twice as high in urban areas for similar reasons
Migration and ethnicity factors in schizophrenia risk
1st and 2nd generation immigrants show a 3x higher risk of schiz compared to natives.
This varies with populations with black Caribbean and African populations showing the highest rates (4-6x risk compared to white British) –> not understood why
Adverse life experiences in schiz risk
Sexual or physical abuse increases the risk of schizophrenia (Read et al 2005)
Psychological treatment for this may be an important part of the management
Premorbid personality in schizophrenia
1/4 patients with schiz will have had premorbid schizoid personality preceding development of schizophrenia
Schizotypal disorder is also commonly associated, possibly due to a shared genetic basis
Theories of schizophrenia
Neuro-developmental theories
Neuro-transmitter theories
Psychological theories
Neurodevelopmental theories of schizophrenia
Schiz pts have enlarged ventricles and smaller, lighter brains –> but no gliosis indicated it is not degenerative
Premorbid low IQ and learning, memory and executive function.
This may then interact with factors during development to lead to overt schizophrenic symptoms
Neurotransmitter theories of schizophrenia
The dopamine hypothesis argues that mesolimbic DA over-activity is responsible for positive symptoms and negative symptoms are due to mesocortical DA under-activity
All antipsychotics are D2 antagonists, and work best on positive symptoms - DA agonists also produce psychosis
Psychological theories of schizophrenia
These argue that deficits in thinking producing a tendency to jump to conclusions and form overly valued ideas is the source of delusions.
Delusions may also develop out of the desire to rationalise hallucinations –> aberrant salience hypothesis
High expressed emotion
This is a type of familial relationship where relatives are highyl critical or overly involved in the persons life
Kavanagh 1992 showed that this was an important factor in schizophrenic relapse, but did not cause schizophrenia.
Progression of schizophrenia
At risk mental state / prodrome
Acute phase –> characterised by positive symptoms
Chronic phase –> negative symptoms are more obvious
It is now known that this is not a fixed chronological progression and negative symptoms may predate positive
Prodromal state/at risk state
This indicates people at high risk of developing schizophrenia, but it is not inevitable
Low grade negative symptoms –> lack frank psychosis
May deny vague positive symptoms for fear of their significance
Positive symptoms of schizophrenia
Hallucinations
Delusions
Thought disorder
Negative symptoms of schizophrenia
Apathy or avolition Flattened or blunted affect Anhedonia Poverty of movement, thought and speech Social withdrawal
Hallucinations
A percept without a stimulus, as opposed to an illusion which is a mis-interpretation of stimulus.
As all perception is interpretation this distinction is of limited use
Can be of any modality but most commonly auditory 2nd/3rd person –> may be arguing, commentary, to you or thought echo
Delusions
A fixed, usually false over-valued idea or belief which is not culturally explicable
May be delusional perception, passivity phenomena or thought interference
Delusional perception
A real perception is used to reach an entirely delusional conclusion
The sky was red so my wife is cheating on me
Passivity phenomena
Can be of thought, affect, impulse, sensation or movement
‘I’m angry but its not my thoughts’
‘They are making my arms move’
Thought interference
The patient believes that their thoughts are being controlled:
Withdrawal–> ‘people keep plucking the thoughts from my head’
Insertion–> ‘the aliens are putting thoughts in my head’
Broadcast–> ‘people are listening to my thoughts’
Formal thought disorder
The form and organisation of thoughts is disrupted
There is loosing of associations and vagueness may progress to full ‘word salad’
This may progress to poverty of thought where few thoughts are had at all
Acute phase of schizophrenia
Striking and florid psychosis
Hallucinations and delusions, patient may appear manic, distracted or paranoid –> thoughts may be very disordered
Negative symptoms can also be present but are less visible
Thought echo
An auditory hallucination where the patient hears a voice echoing all there thoughts
2nd person auditory hallucinations
Where a voice is talking to you
Almost always distressing and ego-dystonic (against the patient)
May tell them to do something
This may underly much of the crime committed by schizophrenics
3rd person auditory hallucinations
Often a conversation between two people about you
May also be a commentary –> major risk of suicide
Generally unpleasant and ego-dystonic
Pseudohallucinations
These are voices heard by the patient, but within their own mind, and usually the voices of people they know (eg parents or partner)
Usually not schizophrenic but may be due to anxiety disorders
Chronic phase
After acute psychotic episodes some patients do not recover but remain ill in a ‘burnt out’ state where negative symptoms are much more prominent
This is easy to confuse with post-psychosis depression, schizoaffective disorder or side effects from medication
Paranoid schizophrenia
Most common type with hallucinations and delusions which will have a paranoid/persecutory element, such that there is a complex and absurd set of beliefs about who and why people want to hurt them
Can lead to violence
Catatonic schizophrenia
Dominated by psychomotor disturbances: Stupor/general catatonia Excitement/motor hyperactivity Posturing, rigidity and waxy flexibility Preservation and obedience
Waxy flexibility
A type of psychomotor disturbance:
The patient is offers no resistance to positioning, and will hold uncomfortable positions for hours (cataplexy)
It may co-occur with rigidity (holding a posture rigidly against pressure) or posturing (assuming & maintaining bizarre positions)
Hebephrenic schizophrenia
Early onset between 15-25
Lacking prominent hallucinations or delusions but significantly disorganised and chaotic mood, behaviour and speech
Affect is labile, inappropriate and superficial
The patients behaviour may seem aimless
Simple schizophrenia
Negative symptoms only without ever having had positive psychosis
Residual schizophrenia
The prominent negative symptoms that remain after positive symptoms subside
First rank symptoms of schizophrenia
First described by Schneider
Auditory hallucinations –> 3rd person conversation, running commentary, or Thought echo
Delusions–> delusional perception, passivity or thought interference
Differential diagnosis for schizophrenia
Organic causes of psychosis Acute/transient psychotic episode Mood disorders Or Schizoaffective disorder Persistent delusional disorder Schizotypal personality disorder
Organic causes of psychosis
In the elderly dementia or delirium
Temporal lobe epilepsy
Substance misuse/withdrawal (alcohol, amphetamine, LSD, ecstasy, ketamine or PCP) or (steroids, DA agonists)
Brain tumour, stroke, HIV, Wilson’s disease, neurosyphillis
Acute and transient psychotic episode
Presents identically to schizophrenia but resolves within a few months
Mood disorders
Both depression and mania, when severe enough can cause psychosis
Schizophrenia should not be diagnosed unless it preceded the affective symptoms
Schizoaffective disorder
Occurs when schizophrenic and affective symptoms occur to a roughly equal level at roughly equal time.
A questionable diagnosis as each set of symptoms can lead to the other secondarily and the two syndromes can co-occur
Persistent delusional disorder
A syndrome where the patient suffers from persistent delusions but few if any hallucinations
Schizotypal personality disorder
A cluster A personality disorder
A lifelong state of eccentricity with abnormal thoughts and affect
May be cold, aloof and suspicious
Do not show definite symptoms of schizophrenia but may develop it later
Schizoid personality disorder
A type A personality disorder
It presents as people who are anhedonic, limited emotional range, socially isolated but this doesn’t concern them.
Little interest in sexual or close relationships
Usually have extensive fantasy world
Antipsychotic medications
All have D2 receptor antagonism –> linked to efficacy of positive symptom block
Extra pyramidal side effects are inevitable with higher levels of DA block but are rarer with atypical antipsychotics –> each drug has other side effects based on actions at other receptors
‘Typical’ antipsychotics
Old drugs such as –> chlorpromazine, haloperidol and flupentixol
Cause significant EPSEs
Widely used because they are cheap and can be given as depot doses
‘Atypical’ antipsychotics
Newer drugs which lacks the EPSEs and don’t tend to raise prolactin levels but still have significant side effects
Still block D2 receptors but also block 5HT2 receptors
Olapzepine, amisulpride, risperidone, quetiapine, aripiprazole, clozepine
Atypical antipsychotics are generally used for
First line treatment for new onset psychosis
If there are unacceptable side effects from typical APs or if the patient tends to relapse when on typical APs
Risperidone can be given as a depot injection
Antipsychotic side effects
Extrapyramidal & anticholinergic side effects or NMS
Hyperprolatinaemia (mainly in typical antipsychotics)
Weight gain (esp. Olanzepine & clozapine) and hyperlipidaemia
Sedation and increased diabetes risk
Arrhythmias and seizures (clozapine)
NMS (Neuroleptic malignant syndrome)
A rare and serious response to DA block causing dystonia, altered consciousness and autonomic disregulation
Raised creatine kinase and WCC –> may die from AKI or rhabomyolyisis
Require stop of AP and ICU treatment
Extra pyramidal side effects
Dystonia –> an involuntary, painful muscle spasm
Akathisia –> an unpleasant feeling of internal restlessness
Parkinsonism–> resting tremor, rigidity and bradykinesia
Tardive dyskinesia–> involuntary, rhythmic movements of limbs or face including grimaces or sucking movements
How do you treat EPSEs?
Earliest onset side effects,dystonia, treat with anti-Ach (procyclidine) –> Later onset akathisia (Tx with B-blocker or benzos) or Parkinsonism (anti-Ach procyclidine) or both by lowering or changing AP, this can also work for tardive dyskinesia but anti-Ach make worse and may be irreversible
Types of dystonia
Torticollis –> neck is twisted to one side
Oculogyric–> eyes twist up so patient cannot look down
Other rarer types may occur
If a patient is on anti-psychotic what should you monitor?
Generally: BP, FBC, U+E, lipids and diabetic screens
BMI and waist size for olanzepine or clozapine
Prolactin levels in typical AP or risperidone
ECG to monitor QTc interval in patients who are elderly or middle aged or on clozapine/high doses
Clozapine
An atypical antipsychotic
It is used as a drug treatment for treatment resistant schizophrenia
It can work when everything else has failed but has a 0.7% risk of agranulocytosis, must be monitored and 3% must stop clozapine
Treatment resistance
Failure to respond to 2 or more antipsychotics, at least 1 of which must be atypical, each given at therapeutic dose for at least 6 weeks
Psychological management for schizophrenia
CBT –> should be offered, with an emphasis on reality testing
Family therapy –> reduces relapse rates, useful for reducing high expressed emotion in families
Concordance therapy –> pt is encouraged to think and make choices about their management
Suicide risk in schizophrenia
10% lifetime
Risk is highest in intelligent young men with good premorbid functioning, after the first episode and in the presence of depressive symptoms
Also at risk of self harm, neglect, social decline and exploitation
Risk of violence in schizophrenia
Only a problem in a subgroup of patients
<10% of violent crimes in Britain are committed by a mentally ill person
Risk factors: Hx of violence, drug use, acute psychosis, non-compliance, specific threats to victim, access to weapon, PD
Risk from others to schizophrenic patients
Patients with schizophrenia are 14 times more likely to be victims of a violent crime than be arrested for one
