Schizophrenia Revision Notes
Introduction to Schizophrenia
Diagnosis and Classification of Schizophrenia:
• Schizophrenia is a serious mental disorder experienced by about 1% of the world
population – commonly diagnosed in men, city-dwellers, and lower socio-economic
groups.
Diagnosis and Classification:
• According to the medical approach, in order to diagnose a specific disorder, we
need to distinguish one disorder from another.
• We do this by identifying clusters of symptoms that occur together and classifying
this as one disorder.
• Diagnosis is possible by identifying symptoms and deciding what disorder a person
has.
The two major systems for the classification of mental disorders are:
- World Health Organisation’s International Classification of Disease (ICD-10)
- American Psychiatric Association’s Diagnostic and Statistical Manual edition 5
(DSM-5)
• These differ slightly in their classification of SZ. For example, in the DSM-5 system
one of the so-called positive symptoms must be present for diagnosis whereas two
or more negative symptoms are sufficient under ICD.
• Previous editions of ICD and DSM recognised subtypes of SZ such as paranoid
schizophrenia involved mainly powerful hallucinations and delusions.
• Both DSM-5 and ICD-10 have dropped subtypes because they tended to be
inconsistent, for example someone with a diagnosis of paranoid schizophrenia would
not necessarily show the same symptoms a few years later.
,Positive Symptoms:
• Positive symptoms of SZ are additional experiences beyond those of ordinary
existence.
• Hallucinations are unusual sensory experiences.
• Some hallucinations are related to events in the environment whereas others have
no relationship to what the senses are picking up from the environment, for example
voices heard either talking to or commenting on a person, often criticising them.
• Hallucinations can be experienced in relation to any sense – e.g. seeing distorted
facial expressions or sometimes people or animals that are not there.
• Delusions are irrational belief. These can take a range of forms.
• Common delusions involve being an important historical, political, or religious figure,
such as Jesus or Napoleon.
• Delusions also commonly involve being persecuted, perhaps by government or
aliens.
• Another class of delusions concerns the body. A person may believe that they are
under external control. Delusions can make a person behave in ways that make
sense to them but seem bizarre to others.
, Negative Symptoms:
• Negative symptoms of SZ involve the loss of usual abilities and experiences.
• SZ is characterised by changes in patterns of speech.
• Speech poverty is the emphasis on reduction in the amount and quality of speech in
SZ – sometimes accompanied by a delay in the person’s verbal responses during
conversation.
• Nowadays, there is more emphasis placed on speech disorganisation in which
speech becomes incoherent or the speaker changes topic mid-sentence – this is
classified as a positive system of SZ in DSM-5, whilst speech poverty remains a
negative symptom.
• Avolition can be described as finding it difficult to begin or keep up with goal-
directed activity – for example, actions performed in order to achieve a result.
• People with SZ often have sharply reduced motivation to carry out a range of
activities.
• Andreasen (1982) identified three signs of avolition including:
- Poor hygiene and grooming
- Lack of persistence in work or education
- Lack of energy.
Introduction to Schizophrenia
Diagnosis and Classification of Schizophrenia:
• Schizophrenia is a serious mental disorder experienced by about 1% of the world
population – commonly diagnosed in men, city-dwellers, and lower socio-economic
groups.
Diagnosis and Classification:
• According to the medical approach, in order to diagnose a specific disorder, we
need to distinguish one disorder from another.
• We do this by identifying clusters of symptoms that occur together and classifying
this as one disorder.
• Diagnosis is possible by identifying symptoms and deciding what disorder a person
has.
The two major systems for the classification of mental disorders are:
- World Health Organisation’s International Classification of Disease (ICD-10)
- American Psychiatric Association’s Diagnostic and Statistical Manual edition 5
(DSM-5)
• These differ slightly in their classification of SZ. For example, in the DSM-5 system
one of the so-called positive symptoms must be present for diagnosis whereas two
or more negative symptoms are sufficient under ICD.
• Previous editions of ICD and DSM recognised subtypes of SZ such as paranoid
schizophrenia involved mainly powerful hallucinations and delusions.
• Both DSM-5 and ICD-10 have dropped subtypes because they tended to be
inconsistent, for example someone with a diagnosis of paranoid schizophrenia would
not necessarily show the same symptoms a few years later.
,Positive Symptoms:
• Positive symptoms of SZ are additional experiences beyond those of ordinary
existence.
• Hallucinations are unusual sensory experiences.
• Some hallucinations are related to events in the environment whereas others have
no relationship to what the senses are picking up from the environment, for example
voices heard either talking to or commenting on a person, often criticising them.
• Hallucinations can be experienced in relation to any sense – e.g. seeing distorted
facial expressions or sometimes people or animals that are not there.
• Delusions are irrational belief. These can take a range of forms.
• Common delusions involve being an important historical, political, or religious figure,
such as Jesus or Napoleon.
• Delusions also commonly involve being persecuted, perhaps by government or
aliens.
• Another class of delusions concerns the body. A person may believe that they are
under external control. Delusions can make a person behave in ways that make
sense to them but seem bizarre to others.
, Negative Symptoms:
• Negative symptoms of SZ involve the loss of usual abilities and experiences.
• SZ is characterised by changes in patterns of speech.
• Speech poverty is the emphasis on reduction in the amount and quality of speech in
SZ – sometimes accompanied by a delay in the person’s verbal responses during
conversation.
• Nowadays, there is more emphasis placed on speech disorganisation in which
speech becomes incoherent or the speaker changes topic mid-sentence – this is
classified as a positive system of SZ in DSM-5, whilst speech poverty remains a
negative symptom.
• Avolition can be described as finding it difficult to begin or keep up with goal-
directed activity – for example, actions performed in order to achieve a result.
• People with SZ often have sharply reduced motivation to carry out a range of
activities.
• Andreasen (1982) identified three signs of avolition including:
- Poor hygiene and grooming
- Lack of persistence in work or education
- Lack of energy.
