Schizophrenia:
Classification of Schizophrenia:
● Schizo → latinised from the Greek, ‘to split or cleave’, Phrenia → disordered condition of
mental activity
● Symptoms of SZ:
○ Positive:
■ Hallucinations
■ Delusions
■ Disorganised Speech
■ Grossly disorganised or catatonic behaviour
○ Negative:
■ Speech poverty
■ Avolition
■ Affective flattening
■ Anhedonia
● Classification for SZ in DSM-V:
○ Criterion A symptoms:
■ Two or more of the following each present for a significant portion of time
during a 1-month period:
● Delusions
● Hallucinations
● Disorganised speech
● Grossly disorganised or catatonic behaviour
● Negative symptoms
○ Criterion B symptoms:
■ For a significant time since onset, social/occupational functioning is below
level achieved prior to onset
○ Criterion C symptoms:
■ Duration of signs and disturbances for at least 6 months - with at least 1
month of symptoms
● Classification - ICD-10 (International Classification of Disease Edition 10)
○ Produced by World Health Organisation
○ Mostly used in European Countries
○ Criterion for ICD-10:
■ 2 or more negative symptoms are sufficient for a diagnosis
■ ICD-10 recognises a range of schizophrenic subtypes, some of which have
powerful positive symptoms but relatively fewer negative symptoms
(paranoid SZ)
● Others may have primarily negative symptoms (catatonic SZ)
,Reliability and Validity:
● Reliability:
○ Differences in classification systems:
■ The two major classification systems - ICD-10 and DSM-V have different ways
of classifying/diagnosing SZ
● DSM requires symptoms to be present for 6 months, ICD only 1
month
● ICD places importance on ‘First Rank Symptoms’ (hallucinations,
delusions, thought interruptions), whereas DSM is multiaxial
● The two systems have different subtypes → ICD has 7, DSM has 5
○ Criteria for diagnosis:
■ Clinicians often use different criteria for diagnosis → there is no universally
agreed definition on what SZ is
■ This lack of consensus means definitions of disorders are likely to change
over time and between cultures
● This can lead to misdiagnosis and long-term/tragic outcomes
○ Different subtypes:
■ There can sometimes be a blurred distinction between subtypes - an
individual may not fit neatly into one category
● Some people may not fit into any of the categories at all
● Validity:
○ Schizophrenia-like disorders:
■ Some sufferers show symptoms similar to those of SZ but do not exactly fit
the criteria
■ Both DSM and ICD have a further set of disorders to cover this:
● Schizophreniform Psychosis
● Schizoaffective Disorder
● Schizotypal Disorder
● Schizoid Personality Disorder, etc
■ Highlights how difficult it is to validly diagnose the disorder
○ Dimensional/categorical:
■ Some psychologists believe that SZ should be seen as dimensional and not
simply categorical
● The classification should relate to the degree to which the problems
are experienced - not just the presence or absence of them
■ Some people have symptoms of SZ (e.g. hearing voices) but are able to cope
with them well
○ Symptom overlap:
■ There are several symptoms which may be characterised as either SZ,
depression, or bipolar disorder
■ This can make it hard for psychiatrists to confidently diagnose SZ
● Ellason & Ross (1955): sometimes people with Dissociative Identity
Disorder can actually exhibit more SZ symptoms than those with SZ
○ Co-morbidity:
■ Refers to when two or more conditions co-occur
, ● Buckley et al. (2009): alongside SZ, depression also occurs in 50% of
patients and 47% of patients also experience substance abuse
● Swets et al. (2014): around 25% of those with SZ suffer from
OCD-like symptoms
■ SZs are also more likely to suffer from secondary non-psychiatric medical
conditions such as hyperthyroidism, asthma, hypertension, and type 2
diabetes
● Gender bias: it is argued that some of the diagnostic criteria in the DSM are biased towards
pathologising one gender over another
○ Broverman et al. (1970): found that US clinicians equalised mentally healthy ‘adult’
behaviour with mentally healthy ‘male’ behaviour
○ Hambrecht et al. (1993): there is also evidence that women are more likely to suffer
symptoms of SZ later than 40 but are not diagnosed as it is rare in males to be
symptomatic at this age
● Cultural bias: ethnic minorities tend to be diagnosed more frequently than white people
● Definitions of abnormality:
○ Unstable:
■ Homosexuality - American Psychiatric Association DSM in 1968 - 1973,
became ‘sexual orientation disturbance’
■ Things defined as abnormal today may be defined differently in the future
○ Not universal:
■ Hearing voices - normal in other cultures
■ Paranoid behaviour - abnormal in Western culture but Mead (1935) found
that this was the norm among Mundugumor people
■ Malinowski (1929) - found in tribes, people wear necklaces of dead
husband’s/father’s jawbones
○ Many behaviours that may be considered abnormal are statistically common -
depression (Statistical Infrequency, pg. 58)
○ Abnormality is defined socially or culturally
● Rosenhan (1973): Being Sane in Insane Places:
○ Aim and Design:
■ Test the hypothesis that psychiatrists cannot reliably tell the difference
between people who are sane and those who are not
■ The first part of the study was a field experiment using participant
observation
● IV - behaviour of the pseudo-patient
■ The second part of the study was experimental
○ Procedure:
■ 8 sane people attempted to gain admissions to 12 hospitals in 5 different
states in America
● Psychology graduate, 3 psychologists, painter, housewife
● 3 women, 5 men
■ Telephoned hospital for appointment, arrived complaining that they are
hearing voices
● Voices said ‘empty’, ‘hollow’, and ‘thud’
Classification of Schizophrenia:
● Schizo → latinised from the Greek, ‘to split or cleave’, Phrenia → disordered condition of
mental activity
● Symptoms of SZ:
○ Positive:
■ Hallucinations
■ Delusions
■ Disorganised Speech
■ Grossly disorganised or catatonic behaviour
○ Negative:
■ Speech poverty
■ Avolition
■ Affective flattening
■ Anhedonia
● Classification for SZ in DSM-V:
○ Criterion A symptoms:
■ Two or more of the following each present for a significant portion of time
during a 1-month period:
● Delusions
● Hallucinations
● Disorganised speech
● Grossly disorganised or catatonic behaviour
● Negative symptoms
○ Criterion B symptoms:
■ For a significant time since onset, social/occupational functioning is below
level achieved prior to onset
○ Criterion C symptoms:
■ Duration of signs and disturbances for at least 6 months - with at least 1
month of symptoms
● Classification - ICD-10 (International Classification of Disease Edition 10)
○ Produced by World Health Organisation
○ Mostly used in European Countries
○ Criterion for ICD-10:
■ 2 or more negative symptoms are sufficient for a diagnosis
■ ICD-10 recognises a range of schizophrenic subtypes, some of which have
powerful positive symptoms but relatively fewer negative symptoms
(paranoid SZ)
● Others may have primarily negative symptoms (catatonic SZ)
,Reliability and Validity:
● Reliability:
○ Differences in classification systems:
■ The two major classification systems - ICD-10 and DSM-V have different ways
of classifying/diagnosing SZ
● DSM requires symptoms to be present for 6 months, ICD only 1
month
● ICD places importance on ‘First Rank Symptoms’ (hallucinations,
delusions, thought interruptions), whereas DSM is multiaxial
● The two systems have different subtypes → ICD has 7, DSM has 5
○ Criteria for diagnosis:
■ Clinicians often use different criteria for diagnosis → there is no universally
agreed definition on what SZ is
■ This lack of consensus means definitions of disorders are likely to change
over time and between cultures
● This can lead to misdiagnosis and long-term/tragic outcomes
○ Different subtypes:
■ There can sometimes be a blurred distinction between subtypes - an
individual may not fit neatly into one category
● Some people may not fit into any of the categories at all
● Validity:
○ Schizophrenia-like disorders:
■ Some sufferers show symptoms similar to those of SZ but do not exactly fit
the criteria
■ Both DSM and ICD have a further set of disorders to cover this:
● Schizophreniform Psychosis
● Schizoaffective Disorder
● Schizotypal Disorder
● Schizoid Personality Disorder, etc
■ Highlights how difficult it is to validly diagnose the disorder
○ Dimensional/categorical:
■ Some psychologists believe that SZ should be seen as dimensional and not
simply categorical
● The classification should relate to the degree to which the problems
are experienced - not just the presence or absence of them
■ Some people have symptoms of SZ (e.g. hearing voices) but are able to cope
with them well
○ Symptom overlap:
■ There are several symptoms which may be characterised as either SZ,
depression, or bipolar disorder
■ This can make it hard for psychiatrists to confidently diagnose SZ
● Ellason & Ross (1955): sometimes people with Dissociative Identity
Disorder can actually exhibit more SZ symptoms than those with SZ
○ Co-morbidity:
■ Refers to when two or more conditions co-occur
, ● Buckley et al. (2009): alongside SZ, depression also occurs in 50% of
patients and 47% of patients also experience substance abuse
● Swets et al. (2014): around 25% of those with SZ suffer from
OCD-like symptoms
■ SZs are also more likely to suffer from secondary non-psychiatric medical
conditions such as hyperthyroidism, asthma, hypertension, and type 2
diabetes
● Gender bias: it is argued that some of the diagnostic criteria in the DSM are biased towards
pathologising one gender over another
○ Broverman et al. (1970): found that US clinicians equalised mentally healthy ‘adult’
behaviour with mentally healthy ‘male’ behaviour
○ Hambrecht et al. (1993): there is also evidence that women are more likely to suffer
symptoms of SZ later than 40 but are not diagnosed as it is rare in males to be
symptomatic at this age
● Cultural bias: ethnic minorities tend to be diagnosed more frequently than white people
● Definitions of abnormality:
○ Unstable:
■ Homosexuality - American Psychiatric Association DSM in 1968 - 1973,
became ‘sexual orientation disturbance’
■ Things defined as abnormal today may be defined differently in the future
○ Not universal:
■ Hearing voices - normal in other cultures
■ Paranoid behaviour - abnormal in Western culture but Mead (1935) found
that this was the norm among Mundugumor people
■ Malinowski (1929) - found in tribes, people wear necklaces of dead
husband’s/father’s jawbones
○ Many behaviours that may be considered abnormal are statistically common -
depression (Statistical Infrequency, pg. 58)
○ Abnormality is defined socially or culturally
● Rosenhan (1973): Being Sane in Insane Places:
○ Aim and Design:
■ Test the hypothesis that psychiatrists cannot reliably tell the difference
between people who are sane and those who are not
■ The first part of the study was a field experiment using participant
observation
● IV - behaviour of the pseudo-patient
■ The second part of the study was experimental
○ Procedure:
■ 8 sane people attempted to gain admissions to 12 hospitals in 5 different
states in America
● Psychology graduate, 3 psychologists, painter, housewife
● 3 women, 5 men
■ Telephoned hospital for appointment, arrived complaining that they are
hearing voices
● Voices said ‘empty’, ‘hollow’, and ‘thud’
