ICD-10
At present two similar yet unidentical diagnostic systems coexist for mental disorders.
These are: International classification of diseases and related health problems, 10th revision (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5).
ICD-10
Founded and approved by WHO (1948), the ICD-10 is used on a global scale in efforts to minimise the disease burden associated with mental disorders. It is multilingual and available via a range of different resources with significant discounts given to less fortunate countries. Currently, the 11th edition of the ICD is under development.
How is it used to diagnose depression?
According to the ICD-10, classification is dependant upon the duration and severity of symptoms. These include the 3 core symptoms, and other depressive symtoms (Table 1). To make a formal diagnosis of depression 4/10 symptoms must be present. Regardless of severity, symptoms must be present for atleast 2 weeks. Table 2 demonstrates how ICD-10 classifies the severities of depression.
Table 2 : Determintaion of severity of depression according to ICD-10