[2] Schizophrenia Flashcards
What is the most common psychotic condition?
Schizophrenia
What is schizophrenia characterised by?
Hallucinations, delusions, and thought disorders, which lead to functional impairment
What does schizophrenia occur in the absence of?
Organic disease, alcohol, and drug-related disoders
Can schizophrenia be secondary to an elevation or depression of mood?
No
What factors does the development of schizophrenia involve>
Both biological (including genetic) and environmental factors
What does the dopamine hypothesis of schizophrenia state?
That schizophrenia is secondary to over-activity of the mesolimbic dopamine pathways in the brain
What evidence supports the dopamine hypothesis of schizophrenia?
- Conventional antipyschotics work by blocking dopamine receptors
- Drugs that potentiate the pathway, for example anti-parkinonian drugs, cause psychotic symptoms
What is the stress-vulnerability model of schizophrenia?
The stress-vulnerability model predicts that schizophrenia occurs due to environmental factors interacting with a genetic predisposition (or brain injury). Patients have different vulnerabilities, so different individuals need to be exposed to different levels of environmental factors to become psychotic
What can the risk factors for schizophrenia be categorised into?
Biological, psychological, and social, or predisposing, precipitating, and perputating
What are the biological predisposing risk factors for schizophrenia?
- Genetic predisposition
- Neurodevelopmental problems, including intrauterine infection, premature birth, fetal brain injury, or obstetric complications
- Age 15-35
- Extremes of parental age (<20 years or >35 years)
What are the biological precipitating risk factors for schizophrenia?
Smoking cannabis or using psychostimulants
What are the biological perpetuating risk factors for schizophrenia?
- Substance misuse
- Poor compliance to medication
What are the psychological predisposing risk factors for schizophrenia?
- Family history (due to exposure to the person with schizophrenia)
- Childhood abuse
What are the psychological precipitating risk factors for schizophrenia?
- Adverse life events
- Poor coping style
What are the psychological perpetuating risk factors for schizophrenia?
Adverse life events
What are the social predisposing risk factors for schizophrenia?
- Substance misuse
- Low socioeconmic status
- Migrant population
- Living in an urban area
What are the social precipitating risk factors for schizophrenia?
Adverse live events
What are the social perpetuating risk factors for schizophrenia?
- Lack of social support
- Expressed emotions
What can the symptoms of schizophrenia be divided into?
- The positive symptoms (acute syndrome), where there is appearance of hallucinations and delusions
- Negative symptoms (the chronic syndrome), which refers to loss of function
What do the clinical features of schizophrenia depend on?
The type of schizophrenia
What are the positive symptoms of schizophrenia?
- Delusions
- Hallucinations
- Formal thought disorder
- Passitivity phenomenon
What is a delusion?
A fixed false belief, which is firmly held despite evidence to the contrary, and goes against the individuals normal social and cultural belief system
Of what nature are the delusions in schizophrenia often?
Persecutory, grandiose, nihilistic, or religious
What are ideas of reference?
Thoughts where a person thinks that common events refer to them directly, e.g. personal messages on TV
What are hallucinations?
Perceptions in the absence of an external stimulus
What kind of hallucination is most common in schizophrenia?
Third person auditory hallucinations
What is a formal thought disorder?
An abnormality in the way that thoughts are linked together
What is thought interference?
When the patient thinks that their thoughts are being inserted (thought insertion), removed (thought withdrawal), or heard out loud by others (thought broadcast)
What is meant by passitivity phenomenon?
When patients believe that their actions, feelings, or emotions are being controlled by an external force
What are the negative symptoms of schizophrenia?
- Avolition
- Asocial behaviour
- Anhedonia
- Alogia
- Blunted affect
- Attention deficit
What is avolition?
A reduced ability, or inability, to initiate and persist in goal-directed behaviour
What is asocial behaviour?
Loss of drive for any social engagements
What is anhedonia?
A lack of pleasure in activities which were previously enjoyable to the patient
What is alogia?
A quantitative and qualitative decrease in speech
What is meant by blunted affect?
Diminished or absent capacity to express feelings
What is meant by attention deficit?
Problems with attention, language, memory, and executive function
What are the types of schizophrenia?
- Paranoid schizophrenia
- Post schizophrenic depression
- Hebephrenic schizophrenia
- Catatonic schizophrenia
- Simple schizophrenia
- Undifferentiated schizophrenia
- Residual schizophrenia
What is paranoid schizophrenia?
The most common form of schizophrenia, that is dominated by positive symptoms
What is post-schizophrenia depression?
When depresion predominantes, with a schizophrenic illness in the past 12 months, with some schizophrenia symptoms still present
What is hebephrenic schizophrenia?
When thought disorganisation predominantes
How does hebephrenic schizophrenia differ from other forms?
The onset of illness is earlier (15-25 years) and has a poorer prognosis
What is catatonic schizophrenia?
A rare form of schizophrenia characterised by one or more catatonic symptoms
What is simple schizophrenia?
A rare form where negative symptoms develop without psychotic symptoms
What is undifferentatied schizophrenia?
When the person meets the diagnostic criteria for schizophrenia, but does not conform to any of the other subtypes
What is residual schizophrenia?
When there has been 1 year of chronic negative symptoms, preceded by a clear-cut psychotic episode
What are the ICD-10 diagnostic criteria for schizophrenia?
A person should have at least 1 very clear symptom from group A, and two or more from group B for at least 1 month
Group A;
- Thought echo/insertion/withdrawal/broadcast
- Delusions of control, influence, or passitivity phenomenon
- Running commentary auditory hallucinations
- Bizarre, persistent delusions
Group B;
- Hallucinations in other modalities that are persistent
- Thought disorganisation (loosening of association, neologisms, incoherence)
- Catatonic symptoms
- Negative symptoms
Schizophrenia should not be diagnosed in the presence of an organic brain disease
What is done in the investigation of schizophrenia?
- History
- MSE
- Blood tests to rule out organic cause
- Urine drug test
- ECG - antipsychotics can cause prolonged QT interval
- CT scan, to rule out organic cause
- EEG, to rule out temporal lobe epilepsy
What blood tests are done in schizophrenia?
- FBC
- TFTs
- Glucose/HbA1c
- Serum calcium
- U&E and LFTs
- Cholesterol
- Vitamin B12 and folate
Why is a FBC done in the investigation of schizophrenia?
To look for anaemia and infection
Why are TFTs done in the investigation of schizophrenia?
Thyroid dysfunction can present as psychosis
Why is glucose/HbA1c done in the investigation of schizophrenia?
Atypical antipsychotics can cause metbaolic syndrome
Why is serum calcium done in the investigation of schizophrenia?
Hypercalcaemia can present as psychosis
Why are U&Es and LFTs done in the investigation of schizophrenia?
Should assess renal and liver function before giving antipsychotics
Why is vitamin B12 and folate done in the investigation of schizophrenia?
Deficiencies can cause psychosis
What are the differential diagnoses of schizophrenia?
- Schizotypical disorder
- Acute and transient psychotic disorders
- Schizoaffective disorder
- Persistent delusional disorder
- Induced delusional disorder
- Mood disorders with psychosis
- Post-partum psychosis
- Late paraphrenia
What is schizotypal personality disorder?
A mental disorder characterised by severe social anxiety, thought disorder, paranoid ideation, derealisation, transient psychosis, and often unconventional beliefs
What is schizoaffective disorder?
A mental disorder characterised by abnormal thought processes and deregulated emotions. The diagnosis is made when a person has features of both schizophrenia and a mood disorder, either bipolar or depression, but does not strictly meet the diagnostic criteria alone
What is postpartum psychosis?
A rare psychiatric emergency in which symptoms of high mood and mania, depression, severe confusion, loss of inhibition, paranoid, hallucinations, and delusions set in, beginning suddenly in the first two weeks after childbirth.
What is paraphrenia?
A mental disorder characterised by an organised system of paranoid delusions, with or without hallucinations, and without deterioration of intellect or personality