Part 1 of Essay
are psychological and behavioral syndromes that deviate significantly from those typical of human beings enjoying good mental health. In general, a mental disorder involves present distress or impairment in important areas of functioning. Such deviations in thought, feelings, and behavior have been recognized throughout h ....

Part 2 of Essay
.... and treatment were developed(3). Classification. The division of into classes is still inexact, and classification varies from country to country. For official record-keeping purposes, most countries follow the International Classification of Diseases of the World Health Organization (WHO). For clinical use in the U. S., the American Psychiatric Association in 1980 adopted a third edition of its Diagnostic and Statistical Manual (DSM-III); an extensive revision (DSM-III-R) was issued in 1987. Most clas ....