There are two main manuals which give details about the categories of dysfunctional behaviour and thus are manuals on how to diagnose dysfunctional behaviour. The International Classification of Diseases (ICD) is probably more widely used, whilst many studies conducted in the UK and US refer to the Diagnostic and Statistical Manual (DSM), which is a specific manual for psychological disorders, whilst the ICD contains one chapter on psychological disorders and is as a whole a manual on health disorders generally.
The DSM is a practical guide based on field trials and empirical research, as well as referring to past editions of both the DSM and ICD. It was produced by the APA and instructs psychiatrists to evaluate the patient in terms of five axes, although the latter two are optional. The axes are as follows: clinical disorders (such as depression), personality disorders (such as mental retardation), physical health (due to recognising that long-term illness, for example, can influence mental health), environmental factors (such as family problems), and global assessment of functioning. These axes reflect an understanding that disorders result from an interaction of biological, psychological and social factors, and thus it is necessary to look at these axes to give a thorough analysis and diagnosis.
The ICD is an international standard diagnostic classification manual, published by the World Health Organisation – it is now in its tenth revision. Chapter 5 is the only chapter relevant for mental and behavioural disorders, as it is a manual for all health disorders. It is more symptom-based than the DSM, and lists clinical and personality disorders on the same axis. There are also 5 more groups of disorders than in the DSM, with ten therefore in total. These axes include: organic mental disorders, delusional disorders, mood disorders, mental retardation, and stress-related and neurotic disorders.