Classification systems validity and reliability

AO1 - What is the ICD

The ICD includes both mental and physical disorders and was first published in 1893

It is multi-lingual and freely available for clinicians around the world

AO1 - How is the ICD split

The ICD is split into chapters and in chapter 5 the ‘f’ code is used for the section of SZ

AO1 - How would clinicians use the ICD

A clinician would conduct an interview where they take out key words which they can look up in the ICD which should lead them to a relevant sub category of a mental disorder

AO1 - What is the DSM

The DSM is a classification system of mental health disorders produced by the American Psychiatric Association

It contains for over 300 disorders and guidelines for diagnosis

AO1 - How is the DSM split

The DSM-5 is divided into 3 sections, section 1 is guidance for diagnosis, section 2 details disorders categorised by similarity of symptoms, finally section 3 provides cultural formulation interview guide to help with diagnosis of the disorders

AO1 - How is diagnosis done with the DSM

Diagnosis involves an unstructured interview and observation to gather info on symptoms which are then compared to the DSM-5

AO3 - Supporting evidence (VALIDITY – DSM + ICD)

One strength of classification systems is that they demonstrate good validity in diagnosis of mental disorders

For the ICD, Mason et al found that the ICD had high predictive validity as it was able to predict outcomes in 99 people 13 years later

This shows that diagnoses made using the ICD are meaningful and reflect real-life outcomes, increasing the validity of the system

For the DSM, Kim-Cohen demonstrated concurrent validity by using interviews and questionnaires on children and their mothers and still obtained the same diagnosis

This suggests that DSM diagnoses are accurate across different methods, increasing confidence in diagnosis.

AO3 - Critique (VALIDITY LIMITATION)

However, validity is reduced due to symptoms overlapping between disorders

For example, disorders such as PTSD have high degree of symptom overlap with other disorders, making accurate diagnosis difficult

This can lead to underdiagnosis or misdiagnosis, reducing the validity of both the DSM and ICD.

AO3 - Supporting evidence (RELIABILITY – DSM + ICD)

Another strength of classification systems is that they can show reliability in diagnosis

For the ICD, Ponizivsky found higher