Schizophrenia is a psychosis- severe mental disorder where contact w reality is
impaired.
CLASSIFICATION OF MENTAL DISORDER- process of organising symptoms into
categories based on which symptoms frequently cluster together.
DIAGNOSIS AND CLASSIFICATION- they are interlinked
Distinguish one disorder from another =identify clusters of symptoms that
occur together=classify as one disorder= then diagnose by identifying
symptoms and deciding which disorder it is
CLASSIFICATION SYSTEMS- ICD- international classification of disease. DSM-
diagnostic and statistical manual they differ slightly- previous editions
recognised subtypes of schizophrenia but these were dropped as they were
inconsistent- someone w symptoms wouldn’t show same symptoms few years
later.
Positive symptoms-atypical symptoms In addition to normal experiences or
distortion of normal functions, for example hallucinations
Hallucinations- unusual sensory experiences Usually hearing or seeing things
that are not there. Most commonly, hearing voices.
Some related to events in environment other bear no relationship w this
(voices heard talking to a person like criticising them/see distorted facial
expressions that aren’t there)
DELUSIONS- beliefs that have no basis in reality/irrational beliefs.
Being an important historical, political, religious figure/persecuted by
gov/aliens/under external control.
They behave in ways that are bizarre to others.
NEGATIVE SYMPTOMS- atypical experiences that represent loss of usual
experience- loss of clear thinking/motivation
SPEECH POVERTY- reduced frequency/quality of speech/delay in verbal
responses in conversation
Speech disorganisation- incoherent/change topic mid sentence- this is a
positive symptom
AVOLITION- (loss of motivation to do tasks/lowered activity levels) diff to keep
up w goal related activity. Poor hygiene, lack of persistence at work, lack energy
, ISSUES IN DIAGNOSIS AND CLASSIFICATION-
STRENGTH- Reliability means consistency. An important measure of reliability is
inter rater reliability- the extent to which 2 different assessors agree on their
assessments. This means 2 mental health professionals arriving at the same
diagnosis of schizophrenia. Test retest reliability- the same clinician reaches
same diagnosis for same individual on 2 occasions. Reliability has now
improved= study= excellent reliability for diagnosis in 180 using DSM= pairs of
interviewers achieved inter rater +.97 and test retest +.92.
Limitation- validity- whether we assess what we are trying to assess- criterion
validity- cheniaux et al (2009) had 2 psychiatrists independently diagnose 100
patients using the DSM & ICD criteria. DSM 39 ICD diagnosed 68. Schizophrenia
is either over/under diagnosed= criterion validity low.
HOWEVER- in 1st study there was excellent agreement between clinicians when
they used 2 measures to diagnose from the same DSM system= criterion
validity is good
LIMITATION- co morbidity Co morbidity is the occurrence of 2 illnesses or
conditions together, e.g schizophrenia and a personality disorder or
depression. If conditions occur together this calls into question the validity of
their diagnosis & classification. Schizophrenia commonly diagnosed w other
disorders. concluded that half of patients with a diagnosis of schizophrenia also
have a diagnosis of depression or substance abuse (47 If very severe
depression looks a lot like schizophrenia, it might be better to see it as one
condition rather than 2 separate. This is therefore a weakness in diagnosing
schizophrenia
LIMITATION- GENDER BIAS- since 1980s men diagnosed more commonly than
women= women less genetically vulnerable than men. Women
underdiagnosed as they have closer relationships= get support=function better.
Women do not receive treatment
LIMITATION- CULTURE BIAS- symptoms have diff meanings in diff cultures.
African Americans & English people of Afro Caribbean origin are several times
more likely than white people to be diagnosed with schizophrenia. Given that
rates in Africa & the West Indies are not that high it is not due to genetic
vulnerability. Diagnosis by psychiatrists from diff cultural
background=overinterpretation of symptoms= discriminated against
LIMITATION- symptom overlap- schizophrenia and bipolar disorder=both have
positive symptoms and neg symptoms. Classification- may not be 2 different
conditions but variations of single condition. Diagnosis- hard to distinguish
from each other. Both are flawed.
impaired.
CLASSIFICATION OF MENTAL DISORDER- process of organising symptoms into
categories based on which symptoms frequently cluster together.
DIAGNOSIS AND CLASSIFICATION- they are interlinked
Distinguish one disorder from another =identify clusters of symptoms that
occur together=classify as one disorder= then diagnose by identifying
symptoms and deciding which disorder it is
CLASSIFICATION SYSTEMS- ICD- international classification of disease. DSM-
diagnostic and statistical manual they differ slightly- previous editions
recognised subtypes of schizophrenia but these were dropped as they were
inconsistent- someone w symptoms wouldn’t show same symptoms few years
later.
Positive symptoms-atypical symptoms In addition to normal experiences or
distortion of normal functions, for example hallucinations
Hallucinations- unusual sensory experiences Usually hearing or seeing things
that are not there. Most commonly, hearing voices.
Some related to events in environment other bear no relationship w this
(voices heard talking to a person like criticising them/see distorted facial
expressions that aren’t there)
DELUSIONS- beliefs that have no basis in reality/irrational beliefs.
Being an important historical, political, religious figure/persecuted by
gov/aliens/under external control.
They behave in ways that are bizarre to others.
NEGATIVE SYMPTOMS- atypical experiences that represent loss of usual
experience- loss of clear thinking/motivation
SPEECH POVERTY- reduced frequency/quality of speech/delay in verbal
responses in conversation
Speech disorganisation- incoherent/change topic mid sentence- this is a
positive symptom
AVOLITION- (loss of motivation to do tasks/lowered activity levels) diff to keep
up w goal related activity. Poor hygiene, lack of persistence at work, lack energy
, ISSUES IN DIAGNOSIS AND CLASSIFICATION-
STRENGTH- Reliability means consistency. An important measure of reliability is
inter rater reliability- the extent to which 2 different assessors agree on their
assessments. This means 2 mental health professionals arriving at the same
diagnosis of schizophrenia. Test retest reliability- the same clinician reaches
same diagnosis for same individual on 2 occasions. Reliability has now
improved= study= excellent reliability for diagnosis in 180 using DSM= pairs of
interviewers achieved inter rater +.97 and test retest +.92.
Limitation- validity- whether we assess what we are trying to assess- criterion
validity- cheniaux et al (2009) had 2 psychiatrists independently diagnose 100
patients using the DSM & ICD criteria. DSM 39 ICD diagnosed 68. Schizophrenia
is either over/under diagnosed= criterion validity low.
HOWEVER- in 1st study there was excellent agreement between clinicians when
they used 2 measures to diagnose from the same DSM system= criterion
validity is good
LIMITATION- co morbidity Co morbidity is the occurrence of 2 illnesses or
conditions together, e.g schizophrenia and a personality disorder or
depression. If conditions occur together this calls into question the validity of
their diagnosis & classification. Schizophrenia commonly diagnosed w other
disorders. concluded that half of patients with a diagnosis of schizophrenia also
have a diagnosis of depression or substance abuse (47 If very severe
depression looks a lot like schizophrenia, it might be better to see it as one
condition rather than 2 separate. This is therefore a weakness in diagnosing
schizophrenia
LIMITATION- GENDER BIAS- since 1980s men diagnosed more commonly than
women= women less genetically vulnerable than men. Women
underdiagnosed as they have closer relationships= get support=function better.
Women do not receive treatment
LIMITATION- CULTURE BIAS- symptoms have diff meanings in diff cultures.
African Americans & English people of Afro Caribbean origin are several times
more likely than white people to be diagnosed with schizophrenia. Given that
rates in Africa & the West Indies are not that high it is not due to genetic
vulnerability. Diagnosis by psychiatrists from diff cultural
background=overinterpretation of symptoms= discriminated against
LIMITATION- symptom overlap- schizophrenia and bipolar disorder=both have
positive symptoms and neg symptoms. Classification- may not be 2 different
conditions but variations of single condition. Diagnosis- hard to distinguish
from each other. Both are flawed.
