Schizophrenia revision
,Introduction to schizophrenia
• Schizophrenia is a severe mental illness where contact with reality and insight are
impaired, an example of psychosis. 1% of the population has schizophrenia, and it is
more common in men, those in urban areas, and those in low socio-economic groups.
• The two main resources for the classification of schizophrenia are the DSM-5 and the
ICD-10. The DSM-5 says that one positive symptom must be present for diagnosis. The
ICD-10 says two or more negative symptoms are enough to diagnose schizophrenia.
• Positive symptoms are additional experiences beyond those of ordinary existence.
Examples include hallucinations (unusual sensory experiences) and delusions
(irrational beliefs).
• Negative symptoms involve the loss of usual abilities and experiences. Examples
include avolition (finding it difficult to keep up with a goal-directed activity) and
speech poverty (reduction in the amount and quality of speech).
, Evaluation of the classification and
diagnosis of schizophrenia
• Strengths- reliability (Osorio et al found excellent reliability using the DSM-5, the inter-rater
reliability was +.97 and test-retest reliability was +.92).
• Weaknesses- validity (lacks criterion validity, different assessment systems arrive at different
diagnoses, Cheniaux et al found people were much more likely to be diagnosed with the ICD than the
DSM, so it is either over-diagnosed in the ICD or under-diagnosed in the DSM), co-morbidity (two
or more conditions occurring together, if conditions occur together a lot of the time they may be
one single condition, Buckley et al found 50% of schizophrenia patients have depression, 47% have
substance abuse, and 23% also have OCD), symptom overlap (considerable overlap of schizophrenia
symptoms with other conditions such as bipolar disorder, using the ICD a person may be diagnosed
with schizophrenia, using the DSM, a person may be diagnosed with bipolar), gender bias (men are
diagnosed much more than women, may be because men are more genetically vulnerable, but Cotton et
al says it could be because women are underdiagnosed as they continue to have good relationships
with family and continue to work), cultural bias (some symptoms have different meanings in
different cultures, such as hearing voices, British people of African-Caribbean origin are up to 9
times more likely to be diagnosed, but rates of schizophrenia in Africa and West Indies is not
particularly high, so Escobar says this is down to cultural bias in psychiatrists from a different
cultural background).
,Introduction to schizophrenia
• Schizophrenia is a severe mental illness where contact with reality and insight are
impaired, an example of psychosis. 1% of the population has schizophrenia, and it is
more common in men, those in urban areas, and those in low socio-economic groups.
• The two main resources for the classification of schizophrenia are the DSM-5 and the
ICD-10. The DSM-5 says that one positive symptom must be present for diagnosis. The
ICD-10 says two or more negative symptoms are enough to diagnose schizophrenia.
• Positive symptoms are additional experiences beyond those of ordinary existence.
Examples include hallucinations (unusual sensory experiences) and delusions
(irrational beliefs).
• Negative symptoms involve the loss of usual abilities and experiences. Examples
include avolition (finding it difficult to keep up with a goal-directed activity) and
speech poverty (reduction in the amount and quality of speech).
, Evaluation of the classification and
diagnosis of schizophrenia
• Strengths- reliability (Osorio et al found excellent reliability using the DSM-5, the inter-rater
reliability was +.97 and test-retest reliability was +.92).
• Weaknesses- validity (lacks criterion validity, different assessment systems arrive at different
diagnoses, Cheniaux et al found people were much more likely to be diagnosed with the ICD than the
DSM, so it is either over-diagnosed in the ICD or under-diagnosed in the DSM), co-morbidity (two
or more conditions occurring together, if conditions occur together a lot of the time they may be
one single condition, Buckley et al found 50% of schizophrenia patients have depression, 47% have
substance abuse, and 23% also have OCD), symptom overlap (considerable overlap of schizophrenia
symptoms with other conditions such as bipolar disorder, using the ICD a person may be diagnosed
with schizophrenia, using the DSM, a person may be diagnosed with bipolar), gender bias (men are
diagnosed much more than women, may be because men are more genetically vulnerable, but Cotton et
al says it could be because women are underdiagnosed as they continue to have good relationships
with family and continue to work), cultural bias (some symptoms have different meanings in
different cultures, such as hearing voices, British people of African-Caribbean origin are up to 9
times more likely to be diagnosed, but rates of schizophrenia in Africa and West Indies is not
particularly high, so Escobar says this is down to cultural bias in psychiatrists from a different
cultural background).
