Diagnosis and Disorganized schizophrenia – (-) Poor inter-rater reliability
disorganized behavior e.g. not
classification of washing, poor speech, language
Two or more health professionals must agree
on the same diagnosis. In a study two
schizophrenia disturbances psychiatrists independently diagnosed 100
people, they found interrater reliability to be
Classification systems Catatonic schizophrenia – poor.
ICD-10 periods of being immobile,
• Requires 2 or more negative (-) Difference in diagnosing methods
staring blankley or uncontrolled
symptoms: The use of DSM and ICD criteria can lead to
excitement and motor
• Avolition – finds it difficult to get very different diagnosis results of
motivation to carry out an movements. schizophrenia – its much more likely to be
activity diagnosed using ICD than DSM.
• Speech poverty – reduction in Paranoid schizophrenia –
amount and quality of speech persecution delusions, belief (-) Co-morbidity
that people are against them. Two or more conditions occurring together
DSM-5 which can make diagnosis very difficult due to
• Requires positive symptoms Residual schizophrenia – when symptom overlap i.e very severe depression
• Delusions – irrational beliefs can look like schizophrenia and schizophrenia
people have mild symptoms
about a range of things e.g. can look like bipolar disorder. A study found
aliens that around half of patients diagnosed with
• Hallucinations – unusual Undifferentiated
schizophrenia – where people schizophrenia also had a a diagnosis of
sensory experiences i.e. depression.
distorted faces. don’t fit into a category.
, Concordance rates:
Gottesman: Biological
Explanations
• If a sibling has schizophrenia you have a 9% chance of
developing it.
• If an identical twin has schizophrenia you are 48% chance of
(+) Research support from adoption studies
developing it.
Biological children of parents with schizophrenia are
• Entire population = 1%
at a heightened risk even if they grow up in an
adoptive family.
Polygenic (numerous genes involved)
Ripke found that 108 different genetic variations were
(+) Evidence for dopamine
associated with slightly increased risk of schizophrenia
Amphetamines increase dopamine and worsen
meaning its aetioloically hetterogeneous.
schizophrenic symptoms in patients. Antipsychotic
drugs that reduce dopamine activity and reduce
Neural correlates
intensity of symptoms suggesting that dopamine is
• Original dopamine hypothesis – antipsychotics used to treat
involved with schizophrenic symptoms.
schizophrenia caused symptoms like Parkinson’s disease
(associated with low dopamine levels). This suggests that
(-) Environmental influences
schizophrenia may be the result of high dopamine levels in
Environmental factors such as smoking cannabis in
subcortical areas of the brain causing positive symptoms
teenage years is linked to an increased risk of
(hyperdopaminergic).
schizophrenia.
• Updated hypothesis – schizophrenia may also be caused by
Childhood trauma – 67% of people with
low activity of dopamine in the prefrontal cortex causing
schizophrenia reported at least one childhood
negative symptoms.
trauma.
disorganized behavior e.g. not
classification of washing, poor speech, language
Two or more health professionals must agree
on the same diagnosis. In a study two
schizophrenia disturbances psychiatrists independently diagnosed 100
people, they found interrater reliability to be
Classification systems Catatonic schizophrenia – poor.
ICD-10 periods of being immobile,
• Requires 2 or more negative (-) Difference in diagnosing methods
staring blankley or uncontrolled
symptoms: The use of DSM and ICD criteria can lead to
excitement and motor
• Avolition – finds it difficult to get very different diagnosis results of
motivation to carry out an movements. schizophrenia – its much more likely to be
activity diagnosed using ICD than DSM.
• Speech poverty – reduction in Paranoid schizophrenia –
amount and quality of speech persecution delusions, belief (-) Co-morbidity
that people are against them. Two or more conditions occurring together
DSM-5 which can make diagnosis very difficult due to
• Requires positive symptoms Residual schizophrenia – when symptom overlap i.e very severe depression
• Delusions – irrational beliefs can look like schizophrenia and schizophrenia
people have mild symptoms
about a range of things e.g. can look like bipolar disorder. A study found
aliens that around half of patients diagnosed with
• Hallucinations – unusual Undifferentiated
schizophrenia – where people schizophrenia also had a a diagnosis of
sensory experiences i.e. depression.
distorted faces. don’t fit into a category.
, Concordance rates:
Gottesman: Biological
Explanations
• If a sibling has schizophrenia you have a 9% chance of
developing it.
• If an identical twin has schizophrenia you are 48% chance of
(+) Research support from adoption studies
developing it.
Biological children of parents with schizophrenia are
• Entire population = 1%
at a heightened risk even if they grow up in an
adoptive family.
Polygenic (numerous genes involved)
Ripke found that 108 different genetic variations were
(+) Evidence for dopamine
associated with slightly increased risk of schizophrenia
Amphetamines increase dopamine and worsen
meaning its aetioloically hetterogeneous.
schizophrenic symptoms in patients. Antipsychotic
drugs that reduce dopamine activity and reduce
Neural correlates
intensity of symptoms suggesting that dopamine is
• Original dopamine hypothesis – antipsychotics used to treat
involved with schizophrenic symptoms.
schizophrenia caused symptoms like Parkinson’s disease
(associated with low dopamine levels). This suggests that
(-) Environmental influences
schizophrenia may be the result of high dopamine levels in
Environmental factors such as smoking cannabis in
subcortical areas of the brain causing positive symptoms
teenage years is linked to an increased risk of
(hyperdopaminergic).
schizophrenia.
• Updated hypothesis – schizophrenia may also be caused by
Childhood trauma – 67% of people with
low activity of dopamine in the prefrontal cortex causing
schizophrenia reported at least one childhood
negative symptoms.
trauma.
