reliability and validity of DSM V

Question 1

what is DSM?

Answer 1

• a diagnostic manual which describes the symptoms, features and assocaited risk factors with over 300 mental and behavioural disorders arranged into 22 categories
• it is based on a classification system that was used to identify disorders experienced by WW2 soilders and was first published in 1952 but has been revides many times since then
• the DSM provides an important first step on the journey to appropriate support however erroneous diagnosis can lead to labelling, stigmitisation and ineffective treatement

Question 2

the three sections of DSM-V

Answer 2

• section 1 - offers guidance about using the new system
• section 2 - details the disorders and is categorised according to our current understanding of underlying causes and similarities between the symptoms. for some disorders, such as schizophrenia, the symptoms are examined differently in DSM-V than previously. the five subtypes, e.g., paranoid and catatonic, have been removed and a dimensional assessment has been added. this allows for the independant measurement of the level, number and duration of symptoms
• section 3 - includes suggestions for new disorders (e.g., internet gaming disorders), which currently require further investigation. it also includes information about the impact of culture on the presentation of symptoms and the way they are communicated, especially when the clinician is from a different cultural background

Question 3

making a diagnosis using the DSM

Answer 3

• clinicians may gather information about an individual through observation but most of the diagnosis will be based on unstructured clinical interviews
• there are also many structured interview schedules available based on the symptom lists, such as the Beck Depression inventory which has 21 questions each with at least 4 possible responses
• the diagnostic process often involves ruling out disorders which do not match the person’s symptoms sufficiently before deciding which disorder offers the ‘best fit’ for the individual
• whilst diagnosis for uncomplicated problems may be achieved in 10 mins by a GP, in difficult cases this may take weeks or months in order to undertsnad the consistency of symptoms over time

Question 4

how reliability is assessed using the DSM

Answer 4

• robert spitzer introduced the use of Cohen’s kappa to improve the reliability of DSM-III
• this statsistic is written as a decimal and refers to the proportion of people who recieve the same diagnosis when assessed and then re-assessed, either at a later time (test-retest reliability) or by an alterantive practitioner (inter-rater reliability)
• Spitzer and his colleagues felt that when agreement was 0.7 between clinicians, this was ‘good agreement’

Question 5

how validity is assessed using the DSM

Answer 5

• over the years, disorders have been removed and added to the different versions of the DSM
• the validity of these labels (diagnoses) have been criticised
• there are multiple types of validitiy relevant to diagnosis - descripitve, aetiological, concurrent and predictive validity
• descriptive validity - when twp people with the same diagnosis exhibit similar symptoms
• aetiological validity - when two people share similar causal factors for a mental health disorder
• concurrent validity - when a clinicna uses more than one method or technique to recah a diagnosis but both methods lead to the same diagnosis
• predictive validity - if a clinician is able to accurately predict outcomes for an individual from their diagnosis e.g., prognosis and reaction to treatment

Question 6

what is meant by reliability of diagnosis?

Answer 6

• the consistency of a diagnosis across clinciians, time and culture
• essentially the same patient should recieve the same diagnosis from multiple clinicians

Question 7

what is meant by validity of diagnosis?

Answer 7

• a valid diagnosis identifies a distinct condition that has symptoms distinclty different from other disorders and suggests a treatment that works
• essentially that the diagnosis is correct and predicts what is truly happening to the patient

Question 8

strength of reliability of DSM - good level of agreement for some disorders

Answer 8

one strength of the DSM-5 is that the field trials demostrate impressive levels of agreement between clinicians for a variety of disorders
for example, Darrel Reiger and colleagues in 2013 reported that three disorders, including post-traumatic stress disorder (PTSD), had kappa values ranging from 0.6 to 0.79 (very good) while seven more diagnoses, including schziophrenia, had kappa values or 0.4-0.59 (good)
therefore, this is important because the criteria for PTSD have changed in terms of the numbers and specific symptoms required to make a diagnosis and it is clear that clinicians have adapted well to these changes

Question 9

weakness of reliability of DSM - falling standards

Answer 9

one weakness of the DSM in terms of reliability is that what counts as an acceptable level of agreement has plummeted over the last 35 years
cooper explains in 2014 that the DSM-5 task force classified levels as low as 0.2-0.4 as ‘acceptable’
one of the least reliable diagnoses (0.28) was major depressive disorder foudn by Regier in 2013
therefore, this means that there is evidence which suggests that DSM-V may be less reliable than previous versions and that diagnoses of major depressive disorder for example, may have been made in error, while other cases may have been missed altogether

Question 10

COUNTER AGRUMENT TO weakness of reliability of DSM - falling standards

Answer 10

however, Kupfer and Kraemer in 2012 explained that clinicians who were part of the DSM-V field trials were asked to ‘work as they usually would’ and take clients as they come in order to mirror normal practice
in contrast, DSM-III used carefully screened ‘test’ clients and clinicians were given detailed training
it is therefore unsuprising that the DSM-V trials had lower levels of reliability

Question 11

strength of validity of the DSM

Answer 11

one strength of the DSM-TR was that eviednce supports the validity of certain disorders
for example Julia Kim-Cohen et al in 2005 demonstrated that concurrent validity of conduct disorder (CD) through interviewing children and their mothers, observing the childrens anti-social behaviours and using questionnaires completed by the children’s teachers
specific risk factors, e.g., male, low income and parental psychological disorders were common in many cases suggesting good aetiological validity
furthermore, predictive validity was demonstrated - 5 year old children were significantly more likely to display behavioural and educational difficulties than children aged 7
therefore, this is important as accurate diagnosis could reduce adult mental heakth problems which are frequently preceded by the symptoms of CD

Question 12

weakness of validity of the DSM

Answer 12

one weakness of the DSM in terms of validity is that many psychologists feel than the DSM-5 lacks validity
the publication of DSM-5 led to a storm of criticism from psychiatrists and psychologists claiming that psychiatric diagnosis tellls us nothing about what is causing a disorder
the argument is that naming or classifying a disorder does not actually tell us anything about the causes
the arguments are circular: why is a person hearing voices? because they have schizophrenia. how do we know they have schizophrenia? because they are hearing voices
therefore, it can be seen that the result of a diganosis is just giving an individual a label and tells us nothing about what has caused the mental health disorder

Question 13

strength of reliability of DSM - Study evidence

Answer 13

one strength of the DSM in terms of reliability is that there is study evidence to show that the diagnostic manual is reliable
in 1988 Goldstein examined the effect of gender on diagnosis of schizophrenia
using DSM-IV she re-diagnosed 199 patients, orignally diagnosed with DSM-II as schizophrenic
she asked two other experts to re-diagnose (single blind) a random sample of 8 of the patients using teh case histories with all indication of previous diagnoses removed and found a high level of agreement between the experts
therefore, this means that there is study evidence to show that there is consistency in diagnosis when using DSM manuals to diagnose patients

Question 14

weakness of reliability of DSM - study evidence

Answer 14

one weaknessone of the DSM in terms of reliability is that there is study evidence to show that the diagnostic manual is not as reliable as we may think
Brown (2001) examined DSM IV
two independant interviewers used the anxiety disorders interview schedule for DSM IV on 362 outpatients in Boston, USA
much agreement was found for the diagnosis of anxiety and mood disorders between the two interviewers
disagreement tended to focus on not whether a symptom fitted a criteria but whether the person had enough symptoms, whether they were severe enough or had lasted long enough to gain a diagnosis
this suggests that they agreed on the diagnosis, but differed in opinions - this could result in a less reliable diagnosis for patients on the ‘boundaries’ of diagnosis, particularly for depression and generalised anxiety disorder
therefore, there is study to suggest that clincians opinions can affect the reliability of a patients diagnosis which may negatively affect the patient meaning they may not recieve the treatment that they need