Idiopathic Insomnia

Glossary Idiopathic insomnia (also referred to as childhood-onset insomnia): A form of insomnia that appears to have its onset early in life (‘beginning in childhood if not at birth’) and has a clinical course that is chronic and relatively invariant. Initial insomnia: Difficulty falling asleep in the absence of middle or late insomnia (also referred to as sleep-onset insomnia). Sleep continuity: This term is often used in two interrelated ways. One use is to refer to the extent to which sleep is efficient as regards sleep latency and/or wake after sleeponset measures. The other use specifically refers to the class of variables (in contrast to sleep architecture) that measure sleep ‘performance’ including sleep latency (SL) and/or wake after sleep onset (WASO), number of awakenings (NWAK), total sleep time (TST), and sleep efficiency (a ratio of total sleep time to total time in bed; SE%).