Issues surrounding the classification and diagnosis of OCD Flashcards
Discuss the introduction
It is useful to have some background information before looking specifically at the issues surrounding the classification of diagnosis of OCD. Prior to the 20th century, there was a tendency to label people who behaved in a psychologically abnormal way as ‘mad’ or ‘deviant’. This blanket description failed to take into account different types of abnormal behaviour. We now know that mental disorders can take many different forms and that treatment varies tremendously depending on the particular type of disorder. For this reason, practitioners and researchers working in the field of psychopathology have developed classification systems to help them make an accurate diagnosis.
Discuss the classification
the act of disturbing things into classes or categories of the same type
Discuss the diagnosis
The recognition and identification of a disease or condition by its signs (results of objective tests e.g. blood) and symptoms (subjective reports from patients about how they feel).
There are many benefits of using classification systems in psychopathology. For example, it eases communication between professionals, allows predictions to be made about the causes, prognosis and appropriate treatments and stimulates and guides research. However, there are a number of problems using classification systems for mental disorders which are not found in other branches of medicine. These will affect the reliability and validity of classification and diagnosis of OCD.
The most widely used classification systems in psychopathology are ICD and DSM.
The ICD-10 (tenth edition of the international classification system for diseases) was published in 1991 by the world health organisation and includes 21 chapters, only one of which, chapter 5, is devoted to psychiatry. It is an international document available in most languages. Chapter 5 is divided into 10 main sections and is primarily used for descriptive and classification purposes, rather than diagnosis.
The DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders - fourth edition, text revision) was developed in the USA and is published only in English. The DSM is widely used as a diagnostic tool and is multi-axial. This means patients have to be assessed on 5 different axes (areas of information) which require information about the biological, psychological and social aspects of a person’s condition.
Discuss Reliability
There are issues concerning the reliablity of classification and diagnosis of OCD. Reliability in this context means that each time the classification system is used to diagnose OCD in an individual it should produce the same outcome (test - re- test reliability). For DSM and ICD to be reliable measures for classifying and diagnosing OCD, those using it must be able to agree when a person should or should not be diagnosed as having OCD. Reliability is an important factor in any diagnostic system as it is of little value if it produces inconsistent diagnoses. the classification systems are widely used but are far from being perfectly reliable.
Discuss Validity
Validity refers to the extent to which a diagnostic system assesses something that is real and distinct from other conditions and the extent to which a classification system such as DSM measures what it claims to measure. For example, does a patient who receives a diagnosis of OCD genuinely suffer from that disorder or a different one? There are many types of validity but issues exist about:
a) the extent to which our system of classification and diagnosis is reflecting the true nature of the problems the OCD patient is suffering
b) the prognosis of OCD; (what will happen in the future)
c) the extent to which the proposed treatments for OCD will actually have a positive effect
Classification and diagnosis of OCD must be valid in order for it to be any use at all.
Discuss the issue - the problem of diagnosis
One general problem with trying to diagnose OCD is that diagnosis is heavily reliant on the clients’ subjective report of symptoms. This is unlike the classification of physical illnesses where a clinician can use objective tests to aid diagnosis. People may not produce honest answers, may be embarrassed and worried that their symptoms may indicate a deeper, mental illness or may lack awareness of the severity and frequency of their symptoms. Because of this, reliability and validity are likely to be affected.
Discuss the issue - OCD shares symptoms with other disorders
Certain symptoms of OCD can be found in other disorders. This may affect consistency on different occasions and between clinicians. For example, OCD symptoms can resemble the delusional beliefs of schizophrenia when the nature of the obsessional thoughts is particularly bizarre. However, provided that the clinician makes a careful assessment of the patient’s symptoms, the two disorders are readily distinguishable. Also, obsessions and compulsions occur in a number of other disorders (e.g. eating disorders). However, DSM warns clinicians not to diagnose OCD when the obsessions and compulsions are restricted to another disorder and this is likely to improve reliability.
Discuss the issue - Co-morbidity. OCD often occurs with other mental disorders
OCD is often co-morbid with other anxiety disorders or depression and it can be difficult to disentangle the two disorders. This is a problem for classification based on categories and will affect the reliability of diagnosis. It also a problem for the validity of classification systems. Patients do not fit neatly into the categories, but rather than acknowledging that the methods used to reach diagnostic decisions lack validity, clinicians diagnose two separate disorders.
Discuss the issue - where to draw the line between normality and abnormality
Another factor concerning reliability and validity of OCD diagnosis is to do with establishing where the line is drawn between normality and abnormality. IT has been estimated that 75% of normal adults have fleeting unwanted thoughts and engage in mild checking behaviour. Therefore, obsessive-compulsive behaviours are probably within the spectrum of normal behaviour. OCD is diagnoses when these behaviours become so excessive, distressing and time-consuming that they interfere with everyday living. However, this is subjective and will be determined by clinicians’ interpretations of their patient’s signs and these may be different to other clinicians’ interpretations.
Discuss the issue - limited NHS resources are available for diagnosing OCD
Another factor that may affect reliability and validity is the limited time and resources that are available to many professionals working in the NHS. It is clear that diagnoses are often made by professionals who are rushed and preoccupied with admitting only the most serious of cases in order to safeguard the resources of the institutions they are working for.
Despite these problems there is some evidence for the reliability of diagnosis of OCD. When assessing a patient, a clinician will carry out an interview in order to make a diagnosis. If the interviews are unstructured and informal, reliability tends to be low. However, if semi-structured or structured interviews are used, reliability is much higher. For example, the anxiety disorder interview schedule for DSM-IV was assessed for reliability by Brown et al. They carried out two interviews on 1400 patients with a gap of under 2 weeks before interviews. These interviews were based on the criteria for various anxiety disorders and depression contained in DSM-IV. The inter-rater reliability for OCD was excellent, indicating that this disorder can be diagnosed with high reliability. The most likely explanation is that compulsions provide a clear behavioural indication of the presence of OCD and this assists therapists in diagnosing the condition.
conclude validity
Validity of classification and diagnosis has been assessed in a number of studies. For example, there is some evidence relating to predictive validity, which is the ability to predict the eventual outcome for patients diagnosed with OCD. Thus, there would be high predictive validity if most OCD patients responded to treatment. In fact, however, predictive validity is reduced by the finding that some patients with OCD are harder to treat than others. For example Lochner & Stein - found that OCD with co-morbid tics has an earlier onset than OCD on its own and it was more resistant to drug therapy.
