1- Mental health conditions (Schizophrenia and other psychoses) Flashcards
define psychosis
Definition: a mental state in which reality is greatly distorted or an individual experience a reality different to everyone else
Epidemiology of psychosis
- Relatively common with schizophrenia being the most common
- Higher prevalence of psychosis in black and ethnic minorities
- Variety which present with psychosis
causes of psychosis can be
organic or non organic
non- organic causes of psychosis
schizophrenia
schizotypal disorder
schizoaffective disorder
mood disorder with psychosis e.g bipolar
acute psychotic episode
puerperal psychosis
organic causes of delirium
- drug induced psychosiss
- iatrogenic (medication)
- complex partial epilepsy (tmeproal lobe epilepsiy)
- delirium
- dementia
- infection e.g. general paresis of the insane (GPI-syphilis) , encephalitis
- huntingtons disease
- SLE
- syphilis
- cushings syndrome
- metabolic disorders e.g. VitB12 def and porphyria
psychosis typical presentation
-
Delusions: A fixed false belief, which is firmly held despite evidence to
the contrary and goes against the individual’s normal social and cultural belief system. -
Hallucinations: A perception in the absence of an external stimulus. It
is a common feature of psychosis. -
Thought disorder: An impairment in the ability to form thoughts from logically connected ideas
- Each sentence does not follow on from the previous one
A psychotic episodes
- Can begin quite suddenly or gradually
- Can last days, weeks or months
- Individual doesn’t not usually realise they are psychotic
o They have no insight - Often not picked up by psychiatrist- usually police or family
x3 functional disorders which can present with psychosis
Define Schizophrenia
Schizo (split) phrenia (mind) is the most common psychotic condition, characterized by hallucinations, delusions and thought disorders which lead to functional impairment.
schizophrenia occurs in the absence of
- It occurs in the absence of organic disease, alcohol or drug-related disorders and is not secondary to elevation or depression of mood. i.e. no organic causes (all functional)
risk factors for schizophrenia
Family history
Pregnancy and birth complications (e.g. maternal malnutrition, intrauterine viral infection)
Increased parental age
Illicit substances
Cannabis use
City living
Social isolation
prevalence of schizophrenia
o The incidence of schizophrenia is estimated to be 15 per 100 000 people.
o Peak age of onset is 15–35 years.
o M:F are equally
Onset for men younger than women
causes of schizophrenia
o Predisposing
o Precipitating
o Perpetuating
and
- biological
- e.g. monozygotic twins show 48% concordance
- e.g. dopamine hypothesis
- e.g. obstretic complications - malnutrition and viral infections and pre-eclamps
- social
- substance misuse
- drug use
- low socioeconomic background
- environmental
- adverse life events
- expressed emotion
Dopamine hypothesis hypothesis of schizophrenia
Schizophrenia is secondary to over-activity of mesolimbic dopamine pathways in the brain. This is supported by conventional antipsychotics which work by blocking dopamine (D2) receptors, and by drugs that potentiate the pathway (e.g. anti-parkinsonian drugs and amphetamines) causing psychotic symptoms.
expressed emotion
the theory that those with relatives that are over involved or that make hostile or excessive critical comments are more likely to relapse
Subtypes of schizophrenia
ICD-10 lists six types of schizophrenia:
- Paranoid schizophrenia- most common
- Hebephrenic schizophrenia
- Catatonic schizophrenia
- Undifferentiated schizophrenia
- Residual schizophrenia
- Simple schizophrenia
pathophysiological theories of schizophrenia
1) Neurodevelopmental hypothesis
2) Neurotransmitter hypothesis
1) Neurodevelopmental hypothesis
- People who experience hypoxic brain injury at birth or exposed to viral infections in utero are at greater risk of developing schizophrenia
- Those who smoke cannabis whilst brain is still developing also at higher risk
- Those with temporal lobe epilepsy also at higher risk
Imaging of schizophrenic brains has shown:
Enlarged ventricles
Small amounts of grey matter loss
Smaller brains
2) Neurotransmitter hypothesis
- An excess of dopamine and overactivity in the mesolimbic system is believed to cause the positive symptoms of schizophrenia. Dopamine antagonists are therefore used to treat schizophrenia.
- There is also thought to be less dopamine activity in the mesocortical tracts, causing the negative symptoms in schizophrenia. This explains why dopamine antagonists are more successful at treating positive than negative symptoms.
- Psychotic symptoms are seen in people with Parkinson’s disease if they are overtreated with levodopa as this increases the amount of dopamine in the brain. Amphetamines and cocaine also increase dopamine release and lead to psychosis.
- Dopamine is not the only neurotransmitter implicated in schizophrenia. There is also an increase in serotonin activity and a decrease in glutamate activity
2) Neurotransmitter hypothesis
- An excess of dopamine and overactivity in the mesocorticolimbic system is believed to cause the positive symptoms of schizophrenia. Dopamine antagonists are therefore used to treat schizophrenia.
- There is also thought to be less dopamine activity in the mesocortical tracts, causing the negative symptoms in schizophrenia. This explains why dopamine antagonists are more successful at treating positive than negative symptoms.
- Psychotic symptoms are seen in people with Parkinson’s disease if they are overtreated with levodopa as this increases the amount of dopamine in the brain. Amphetamines and cocaine also increase dopamine release and lead to psychosis.
- Dopamine is not the only neurotransmitter implicated in schizophrenia. There is also an increase in serotonin activity and a decrease in glutamate activity
what causes the positive symptoms of schizophrenia
An excess of dopamine and overactivity in the mesolimbic system is believed to cause the positive symptoms of schizophrenia.
Dopamine antagonists e.g. antipsychotics, are therefore used to treat schizophrenia.
what causes the negative symptoms of schizophrenia
thought to be less dopamine activity in the mesocortical tracts , causing the negative symptoms in schizophrenia.
This explains why dopamine antagonists are more successful at treating positive than negative symptoms.
ICD-10 criteria for schizophrenia
ICD-10 can be used to give a framework for diagnosis.
In patients suffering from a psychotic episode lasting for at least one month, schizophrenia may be diagnosed if one (or more) of the following is present:
- Thought echo, thought insertion or withdrawal, or thought broadcasting.
- Delusions of control, influence or passivity, clearly referred to body or limb movements or specific thoughts, actions, or sensations; delusional perception.
- Hallucinatory voices giving a running commentary on the patient’s behaviour, or discussing him between themselves, or other types of hallucinatory voices coming from some part of the body.
- Persistent delusions of other kinds that are culturally inappropriate and completely impossible (e.g. being able to control the weather, or being in communication with aliens from another world).
Or it may be diagnosed in patients suffering from a psychotic episode lasting for at least one month if two (or more) of the following are present:
- Persistent hallucinations in any modality, when occurring every day for at least one month, when accompanied by delusions (which may be fleeting or half-formed) without clear affective content, or when accompanied by persistent over-valued ideas.
- Neologisms, breaks or interpolations in the train of thought, resulting in incoherence or irrelevant speech.
- ** Catatonic behaviour** such as excitement, posturing or waxy flexibility, negativism, mutism and stupor.
- Negative symptoms such as marked apathy, paucity of speech, and blunting or incongruity of emotional responses (it must be clear that these are not due to depression or to neuroleptic medication).
MSE for schizophrenia
overview of management of schizophrenia
Involves and MDT and biopsychosocial approach including: care programme approach, voluntary and compulsory hospital admission, antipsychotic medication and psychological treatments
biological approach to schizophrenia
psychological approach to schizophrenia
social approach to schizophrenia
typical antipsychotics examples
Older and caused generalised dopamine receptor blockade i.e. blocked all dopaminergic pathways
- Haloperidol
- Chlorpromazine
- Flupentixol decanoate (depot injection)
course of psychotic epsiodes
