The Diagnostic and Statistical Manual of Mental Disorders is the bible of abnormal psychology. It lists a set of disorders and provides detailed descriptions on what constitutes a disorder such as Major Depression or Anxiety Disorder.
It also gives general descriptions of how frequent the disorder occurs in the general population, whether it is more common in males or females and other such facts. The diagnostic process uses five dimensions called 'axes' to ascertain symptoms and overall functioning of the individual. These axes are as follows:
Axis I - Particular clinical syndromes
Axis II - Personality disorders
Axis III - General medical conditions
Axis IV - Psychosocial/environmental problems
Axis V - Global assessment of functioning (often referred to as GAF)
The most recent version is the 'Text Revision' of the DSM-IV, also known as the DSM-IV-TR, published in 2000.