Issues of validity and reliability in the issue of diagnosis
Reliability = Reliability is whether clinicians are able to give the same diagnosis when presented with the same symptoms. E.g. two patients have the same symptoms but one is diagnosed with schizophrenia and the other bipolar would suggest the diagnosis is unreliable. Reliability is increased if all the practitioners use the same testing tools to make decisions about diagnosis. It also means if using the same diagnostic tool e.g. the DSM, they should all form the same diagnosis if presented with the same symptoms from a patient
Issues occur if:
· Two clinicians do not agree on diagnosis
· the patient does not describe the symptoms first-hand the diagnosis may not be reliable e.g. if a GP passes on information to a psychiatrist the notes that are sent may add in or be put in the GP’s words (patient misinterpreting the GP/ GP misinterprets the patient)
· The symptoms may not remain constant
· Brown (1986) consistency of diagnosis – 21 pp’s interviewed intensively, 10 re-diagnosed from recordings, 11 were interviewed by two interviewers
Validity = whether a course of treatment can be given successfully, and if the same treatment can be used with other patients with the same symptoms e.g. a diagnosis of depression should not include hallucinations; treatment given for depression is effective
Issues occur if:
• If treatment is not successful in treating a disorder
• If more than one cause exists
• Symptoms the patient describes e.g. what they emphasise
• If the patient presents more than one disorder (co-morbidity)
• Lee (2006) however used the DSM-IV to look at diagnosis of Korean children with ADHD. A Questionnaire was given to 48 primary school teachers and 1663 children were rated using 18 ADHD criteria in DSM IV. There was a match between the features of ADHD outlined in the DSM and the responses to the questionnaires, an ADHD test and teacher assessments. This match was not as good for girls as it was for boys. This suggests the DSM is mostly valid as the correct diagnosis and outcome was given.
Issues of culture in diagnosis
1. Culture does not affect diagnosis – the DSM is an objective measure and all cultures should be treated the same way. Lee (2006) found there was a match between features of ADHD outlined in DSM-IV, the teacher responses to a questionnaire, and an ADHD test of children in Korea – this shows the DSM can be used worldwide
The DSM includes culture bound syndromes such as Kuru and Genital Retraction (Penis Panic) which means it does account for cultural differences
By focusing on negative symptoms in schizophrenia which can be objectively measure rather than positive symptoms reduces subjectivity and improves diagnosis
Also removal of vague terms such as ‘bizarreness’ which can be subjective
2. Culture does affect diagnosis as the spiritual model suggests some cultures perceive hearing voices as spiritual whereas western cultures would be likely to consider this as psychotic . This means culture does affect diagnosis and needs to be taken into account
Cultural differences for Schizophrenia
Diagnosing Disorders
The Diagnostic Statistic Manual (DSM) and the International Classification of Diseases (ICD) are the two main manuals used for diagnosing mental disorders. Both manuals are regularly updated, the DSM is in its 5th edition, and the ICD currently in its 10th edition. The DSM is an American manual, while the ICD is used by the World Health Organisation and used in Europe.
The DSM
DSM IV was based on 5 axes.
Axis 1: Considers clinical disorders, mental disorders, developmental disorders and learning disorders.
Axis 2: Underlying personality conditions, including mental retardation
Axis 3: General medical and physical conditions
Axis 4: Psychosocial and environmental factors that affect the disorder.
Axis 5: Global Assessment of Functioning (GAF) scale. This rates patients from 0-100 with how well they can cope with everyday life.
DSM V has removed the 5 axis, along with making other changes including:
Autism spectrum disorder: This incorporates autistic disorder, Asperger’s disorder, childhood disintegrative disorder, and pervasive developmental disorder which were previously listed as separate disorders
Schizophrenia subtypes - paranoid, disorganized, catatonic, and undifferentiated have been removed due to low validity and reliability
Specific learning disorders – this combines the DSM-IV diagnoses of reading disorder, mathematics disorder, disorder of written expression, and learning disorder not otherwise specified into one heading
Excoriation (skin-picking) disorder is new to DSM-5 and will be included in the Obsessive-Compulsive and Related Disorders chapter, which is where OCD will now be located
Hoarding disorder is new to DSM-5. This disorder will help characterize people with persistent difficulty discarding or parting with possessions, regardless of their actual value. The behaviour usually has harmful effects—emotional, physical, social, financial and even legal—for a hoarder and family members.
Eating disorders – the criteria for anorexia nervosa no longer require amenorrhea (the absence of menstruation).
Disruptive mood dysregulation disorder will be included in DSM-5 to diagnose children (under 18’s) who exhibit persistent irritability and frequent episodes of behaviour outbursts three or more times a week for more than a year. The diagnosis is intended to address concerns about potential over-diagnosis and overtreatment of bipolar disorder in children.
Agoraphobia and panic disorder are no longer linked, and are now two unique diagnoses.
Substance related and addictive disorders - DSM-5 has expanded the addictions chapter to include non-substance-related addictions including gambling
Mental retardation has been renamed to "intellectual disability"
The bereavement exclusion has been removed from major depressive disorder – previously symptoms lasting less than 2 months following a bereavement were excluded from a diagnosis of depression. This change to DSM 5 has been included to remove the implication that grief only lasts 2 months, when more commonly it lasts 1-2 years; and also bereavement has been found to be a stressor that can act as a vulnerability factor in triggering depression.
General evaluation points for diagnosis:
A strength of having diagnostic manuals is that it allows a common diagnosis to be give.
The manuals are objective in how they define a disorder, meaning that the same diagnosis should be given universally
However, by splitting a disorder into a list of symptoms makes it reductionist; a holistic approach may be more valid
Also diagnosis can lead to labelling. This may affect the way the person sees themselves and how society treats them. In addition, it can lead to self fulfilling prophecy where the treatment does not work as they keep to the symptoms of their label.
Not everyone believes in treatments, in particular that following the medical model. One psychologist – Laing, suggested that schizophrenia is simply another way of living and a person is trying to get back to their true self, therefore should not be considered an illness.
Reliability = Reliability is whether clinicians are able to give the same diagnosis when presented with the same symptoms. E.g. two patients have the same symptoms but one is diagnosed with schizophrenia and the other bipolar would suggest the diagnosis is unreliable. Reliability is increased if all the practitioners use the same testing tools to make decisions about diagnosis. It also means if using the same diagnostic tool e.g. the DSM, they should all form the same diagnosis if presented with the same symptoms from a patient
Issues occur if:
· Two clinicians do not agree on diagnosis
· the patient does not describe the symptoms first-hand the diagnosis may not be reliable e.g. if a GP passes on information to a psychiatrist the notes that are sent may add in or be put in the GP’s words (patient misinterpreting the GP/ GP misinterprets the patient)
· The symptoms may not remain constant
· Brown (1986) consistency of diagnosis – 21 pp’s interviewed intensively, 10 re-diagnosed from recordings, 11 were interviewed by two interviewers
Validity = whether a course of treatment can be given successfully, and if the same treatment can be used with other patients with the same symptoms e.g. a diagnosis of depression should not include hallucinations; treatment given for depression is effective
Issues occur if:
• If treatment is not successful in treating a disorder
• If more than one cause exists
• Symptoms the patient describes e.g. what they emphasise
• If the patient presents more than one disorder (co-morbidity)
• Lee (2006) however used the DSM-IV to look at diagnosis of Korean children with ADHD. A Questionnaire was given to 48 primary school teachers and 1663 children were rated using 18 ADHD criteria in DSM IV. There was a match between the features of ADHD outlined in the DSM and the responses to the questionnaires, an ADHD test and teacher assessments. This match was not as good for girls as it was for boys. This suggests the DSM is mostly valid as the correct diagnosis and outcome was given.
Issues of culture in diagnosis
1. Culture does not affect diagnosis – the DSM is an objective measure and all cultures should be treated the same way. Lee (2006) found there was a match between features of ADHD outlined in DSM-IV, the teacher responses to a questionnaire, and an ADHD test of children in Korea – this shows the DSM can be used worldwide
The DSM includes culture bound syndromes such as Kuru and Genital Retraction (Penis Panic) which means it does account for cultural differences
By focusing on negative symptoms in schizophrenia which can be objectively measure rather than positive symptoms reduces subjectivity and improves diagnosis
Also removal of vague terms such as ‘bizarreness’ which can be subjective
2. Culture does affect diagnosis as the spiritual model suggests some cultures perceive hearing voices as spiritual whereas western cultures would be likely to consider this as psychotic . This means culture does affect diagnosis and needs to be taken into account
Cultural differences for Schizophrenia
- More catatonia in other cultures – 21% in Sri Lanka compared to 5% white British.
- More auditory hallucinations in Mexican born Americans than white Americans – no other differences between the two groups could be found
- Schizophrenia in all countries has more similarities than differences – Lin (1996) – suggests culture does not play a role
Diagnosing Disorders
The Diagnostic Statistic Manual (DSM) and the International Classification of Diseases (ICD) are the two main manuals used for diagnosing mental disorders. Both manuals are regularly updated, the DSM is in its 5th edition, and the ICD currently in its 10th edition. The DSM is an American manual, while the ICD is used by the World Health Organisation and used in Europe.
The DSM
DSM IV was based on 5 axes.
Axis 1: Considers clinical disorders, mental disorders, developmental disorders and learning disorders.
Axis 2: Underlying personality conditions, including mental retardation
Axis 3: General medical and physical conditions
Axis 4: Psychosocial and environmental factors that affect the disorder.
Axis 5: Global Assessment of Functioning (GAF) scale. This rates patients from 0-100 with how well they can cope with everyday life.
DSM V has removed the 5 axis, along with making other changes including:
Autism spectrum disorder: This incorporates autistic disorder, Asperger’s disorder, childhood disintegrative disorder, and pervasive developmental disorder which were previously listed as separate disorders
Schizophrenia subtypes - paranoid, disorganized, catatonic, and undifferentiated have been removed due to low validity and reliability
Specific learning disorders – this combines the DSM-IV diagnoses of reading disorder, mathematics disorder, disorder of written expression, and learning disorder not otherwise specified into one heading
Excoriation (skin-picking) disorder is new to DSM-5 and will be included in the Obsessive-Compulsive and Related Disorders chapter, which is where OCD will now be located
Hoarding disorder is new to DSM-5. This disorder will help characterize people with persistent difficulty discarding or parting with possessions, regardless of their actual value. The behaviour usually has harmful effects—emotional, physical, social, financial and even legal—for a hoarder and family members.
Eating disorders – the criteria for anorexia nervosa no longer require amenorrhea (the absence of menstruation).
Disruptive mood dysregulation disorder will be included in DSM-5 to diagnose children (under 18’s) who exhibit persistent irritability and frequent episodes of behaviour outbursts three or more times a week for more than a year. The diagnosis is intended to address concerns about potential over-diagnosis and overtreatment of bipolar disorder in children.
Agoraphobia and panic disorder are no longer linked, and are now two unique diagnoses.
Substance related and addictive disorders - DSM-5 has expanded the addictions chapter to include non-substance-related addictions including gambling
Mental retardation has been renamed to "intellectual disability"
The bereavement exclusion has been removed from major depressive disorder – previously symptoms lasting less than 2 months following a bereavement were excluded from a diagnosis of depression. This change to DSM 5 has been included to remove the implication that grief only lasts 2 months, when more commonly it lasts 1-2 years; and also bereavement has been found to be a stressor that can act as a vulnerability factor in triggering depression.
General evaluation points for diagnosis:
A strength of having diagnostic manuals is that it allows a common diagnosis to be give.
The manuals are objective in how they define a disorder, meaning that the same diagnosis should be given universally
However, by splitting a disorder into a list of symptoms makes it reductionist; a holistic approach may be more valid
Also diagnosis can lead to labelling. This may affect the way the person sees themselves and how society treats them. In addition, it can lead to self fulfilling prophecy where the treatment does not work as they keep to the symptoms of their label.
Not everyone believes in treatments, in particular that following the medical model. One psychologist – Laing, suggested that schizophrenia is simply another way of living and a person is trying to get back to their true self, therefore should not be considered an illness.