The America Psychological Association (APA) began publishing the Diagnostic and Statistical Manual of Mental Disorders in the 1950s. Since then, the work has gone through several expanded and updated editions, including the fourth edition, known as the DSM-IV, which appeared in 1994. The DSM-5 appeared in 2013, but has yet to gain widespread dissemination.
Professionals in mental health use the DSM-IV when working with adults and children in order to understand a diagnosis of a mental disorder and provide better treatment options. The DSM-IV listed 297 various mental disorders. It was revised in 2000, appearing as the DSM-IV-TR. This edition essential expanded upon diagnosis information and introduced the five-axis system of diagnosis.
Axis I are clinical syndromes, what most people would consider to be the "diagnosis" (depression, or schizophrenia). Axis II are developmental and personality disorders. Developmental disorders, such as autism, are present from childhood, while personality disorders, such as borderline personality, have lasting symptoms that affect the way an individual interacts with the world. Axis III are physical conditions that play a major role in the exacerbation or development of a mental illness. Axis IV is the severity of psychosocial factors, while Axis V rates a person's highest level of functioning.