 In 1979, the first Diagnostic Classification of Sleep and Arousal Disorders (DCSAD) was developed by the Association of Sleep Disorders Centers (ASDC) and the Association for the Psychophysiological Study of Sleep.Disorders were divided into four main categories.In 1990, the first comprehensive classification of disorders of sleep and arousal, the International Classification of Sleep Disorders (ICSD-1990), was developed by the American Academy of Sleep Medicine (AASM) in association with the European Sleep Research Society, the Japanese Society of Sleep Research, and the Latin American Sleep Society.