Diagnosis

What are the 4 Ds of diagnosis?

• Deviance

• Dysfunction

• Distress

• Danger

What are the pros of a method like the 4 Ds existing?

• good for professional use as a classification system

• practical application for use alongside the DSM

Deviance

• Statistical deviance is where behaviour is judged as abnormal based on how rare or statistically infrequent it is. The assumption is that any human characteristic is spread in a normal way across the general population, forming a graphical curve of normal distribution where the majority of people fall at the centre of the graph.

• If someone’s behaviour is not within two standard deviations for the population (falling into the bottom or top 2.5%) then their behaviour is considered statistically abnormal 

• Social norms deviance is where abnormality is judged as socially unacceptable by cultural expectations and societal views. Anyone who deviates from such behaviour is classified as abnormal.  

+/- for Deviance

• (+) Statistical deviance can provide objective, numerical data therefore reducing risk of subjective diagnoses. Makes research more comparable 

• (-) Some characteristics e.g. having a genius-level IQ is statistically infrequent, however is not considered deviant, so the use of deviance may not always be useful in diagnosing mental disorders

• (-) Different cultures have different standards and norms for acceptable behaviours, so therefore social deviance differs in different places 

• (-) The concept of abnormality changes over time, even within the same society, as social norms can change and update 

• (-) Many other factors can influence whether a behaviour is deviant and abnormal, including age/gender of the person or context, subjectivity

Dysfunction

• Abnormal behaviour that tends to impact a person’s ability to function daily ad carry out everyday tasks - perhaps leading to an inability to care for themselves properly 

Rosenhan and Seligman’s (1989) Criteria for Dysfunction 

• Unpredictability/loss of control  

• Irrationality  

• Causes observer discomfort  

• Suffering or distress 

• Maladaptiveness  

• Unconventionality  

• Violates moral standards

+/- Dysfunction

(+) 

• Diagnoses focus on a more individual level at the impacts upon the individual’s life, rather than society’s view of them  

(-) 

• Dangers of misdiagnosing different personal lifestyle choices, can stigmatise cultural differences and promote discrimination 

• Definition of dysfunction is subjective 

• Dysfunction may not be immediately obvious, so the psychiatrist may have to look closely at all aspects of the patient’s life

Distress

• An individuals’ emotional suffering and subjective feelings of pain, anxiety, depression, agitation etc. This is typically intense and prolonged, and occurs in situations without a logical reason for this upset

+/- Distress

(+) 

• Deals with quality of life and personal emotions rather than soley outsider-observed behaviours. This allows the point of view of the patient to be heard, which is empowering for them
  (may also assess the impact on family members etc around them)

(-) 

• Must be used alongside other Ds for diagnosis 

• Subjective and unable to be measured or proven 
  (some individuals may not experience distress from their disorder, but this is actually symptomatic of a mental health condition e.g. psychopaths will not experience distress from their actions due to poverty in affective regions, however this does not mean they are exempt from a diagnosis)

Danger

• When psychologically dysfunctioning behaviour becomes dangerous to oneself or others, with the potential to cause harm.

+/- Danger

(+) 

• Focus on protecting the individual and others, ability to reduce harm 

(-) 

• Needs to utilise the other Ds to help distinguish the motives behind living ‘dangerously’ - whether this is harmful or purely for fun. For example, some risky sports may lead to personal harm, but not a diagnosis of a mental disorder 

What is a measure used to test reliability, and how does it work?

• Cohen’s Kappa – a method of testing whether a diagnosis is reliable or not. The kappa is the proportion of people who receive the same diagnosis when assessed and re-assessed either  
  a) at a later time (test re-test reliability) 
  b) or by an alternative clinician (inter-rater) 
  -- 0.7 value = ‘good agreement’, as this means 70% of diagnoses will match 

• Schizophrenia has a Kappa value of 0.4 - 0.59 

• Field trials of the DSM found a kappa rating of 0.28 for major depressive disorder

Concurrent validity

A clinician uses more than one technique/method to reach a diagnosis and both methods lead to the same diagnosis 

Descriptive validity

Two people with the same diagnosis show similar symptoms 

Predictive validity

A clinician is able to make predictions about how the illness might progress and how they might react to treatments 

Aetiological validity

Two people with the same diagnosis have the same causal factors which led to their symptoms 

How has the validity of the DSM improved?

Revisions and updates keep the diagnostic information relevant and valid, as well as including a third section on up-and-coming research.
Example of an update to how certain disorders are diagnosed includes when the DSM-IV subtypes of schizophrenia (e.g. paranoid, disorganised, catatonic, undifferentiated, and residual) were eliminated, as these subtypes were found not to show distinctive patterns of treatment response. Instead, a dimensional approach to rating severity for the core symptoms of schizophrenia is included in Section II 

What is the ICD

• International Classification of Disease is not just a system for mental health, but all diseases 

• Like the DSM, it has had many revisions over the years, and the current version is the ICD-11 

• Mental disorders under section F, where each mental disorder has its own number, such as 20 for schizophrenia. Clinicians would interview a client, noting down key words that relate to the client’s symptoms 

Comparisons between the ICD and DSM

• The ICD uses a coding system for mental health disorders which allows the clinician to go from general aspects of a disorder to more specific details (codes to differentiate between different subtypes of a disorder). This is different to the DSM, which doesn’t have a coding system  

• The ICD is multilingual, which the DSM is not  

• Both the DSM and ICD take a dimensional approach to diagnose, taking into account family history, dysfunction etc.  

Strengths of the ICD

• Organised, easy to use as it is structured (DSM is chronological) 

• Easy comparison as the ICD can be used across cultures/countries/languages, due to translations being culturally appropriate. Makes it more reliable and valid 

• Reed et al. (2018) found that the vast majority of clinicians answered ‘extremely’ or ‘quite’ for how easy the ICD-11 was to use, showing that it is reliable 

• ICD gives objective criteria for what symptoms each disorder has, thus limiting the subjectivity from the psychiatrist  

Weakness of the ICD

• Relies on patient answering questions from an interview truthfully, and if they do not do so sufficiently, then the ICD will not be useful in diagnosing a disorder. This impacts validity 

• Reduces individual experiences into solely numbers and letters. Individual differences in conditions may make it difficult to classify patients into exact codes, and a more holistic approach may be needed for treatment 

• Some symptoms such as change in appetite are common in a variety of disorders, so if a lot of symptoms are comorbid ICD may not be useful in correctly diagnosing the exact disorder and individual has, reducing the validity 

• Nicholls et al (2000) found that the kappa rating of ICD 10 for eating disorder in children and adolescents was 0.357, which would suggest it is not always a useful diagnostic tool, depending on the disorder and age of the patient 

Differences in diagnoses of schizophrenia between the ICD and the DSM

• The DSM-V-TR requires 2 or more symptoms of schizophrenia for at least 1 month, with general dysfunction persisting for at least 6 months - whereas the ICD only requires the presence of 1 symptom for at least a month, with no minimum duration

• Both have eliminated subtypes of schizophrenia 

What is the DSM?

• The DSM describes symptoms, features and risk factors of over 300 mental and behavioural disorders arranged into 22 categories. 

• Developed in the US  

• Developed in 1952 and now onto its 7^th edition 

• The DSM is useful is a useful reflection tool to see how disorders have changed over time, for example in the DSM-I, homosexuality used to be viewed as a ‘sociopathic personality disorder.’

What are the advantages of having a classification system?

• Consistency between psychiatrists  

• More objective and based on fact rather than subjectivity  

• Faster or easier diagnosis 

What are the disadvantages of having a classification system?

• May lead to categorisation of people 

• Doesn't account for individual differences and behaviours, not everyone may match textbook definition  

• Overdiagnosis with mental disorders that people may not actually have. This could result in treatment with potentially harmful medication that is not needed (influence of large pharmaceutical companies) 

What are the three sections of the DSM?

• Section I – Introduction, providing instruction and general information about using the manual 

• Section II – Diagnostic Criteria and Codes, where the list of mental disorders are classified into 20 categories each defined by symptoms 

• Section III – Emerging Measures and Models, introducing alternative models that are still undergoing research but may shape the content of future DSM editions 

During your studies of clinical psychology, you will have learned about classification systems for mental health, including the DSM and ICD
a) Describe the DSM as a classification system (2)

• The DSM-V has three sections, with section II having the classification of the main mental health disorders

• Within section III, there is a cultural formulation interview guide to help with diagnosis of the disorder. This section also includes current research that may affect future DSM editions

Explain one weakness of the DSM as a classification system to diagnose mental health disorders (2)

• The DSM may not be an accurate classification system for mental disorders as patient factors may affect the information the clinician receives

• This may be because the patient might not tell the clinician certain aspects of their behaviour due to cultural differences or the stigma attached to such behaviours