Types of Insomnia

Glossary Difficulty initiating and maintaining sleep (DIMS): A broad term that includes insomnia with any of the subtypes described above. Idiopathic insomnia: Lifelong insomnia with a presumed organic component. Inadequate sleep hygiene insomnia: A form of insomnia that is conceptualized as being perpetuated, in large measure, by lifestyle issues. Initial insomnia: Difficulty falling asleep in the absence of middle or late insomnia (also referred to as sleep onset insomnia). Insomnia not otherwise specified (NOS): A form of insomnia that is conceptualized as being perpetuated by unknown factors. Late insomnia: Difficulty with early morning awakenings in the absence of initial or middle insomnia (also referred to as terminal insomnia or sleep offset insomnia). Middle insomnia: Difficulty maintaining sleep in the absence of initial or late insomnia (also referred to as sleep maintenance insomnia). Paradoxical insomnia: A form of insomnia for which there is a profound discrepancy between the patient’s experience of sleep continuity disturbance and the measure of insomnia severity by polysomnography. Physiological insomnia: A form of insomnia that is conceptualized as being perpetuated, in large measure, by organic factors. Psychophysiologic insomnia: A form of insomnia that is conceptualized as being perpetuated by both psychological (behavioral and cognitive) and physiological factors. 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 (SL) and/or wake after sleep onset (WASO) measures. The other use specifically refers to the class of variables (in contrast to sleep architecture) that measure sleep ‘performance’ including SL and/or WASO, number of awakenings (NWAK) measures, total sleep time (TST), and sleep efficiency as a percentage measure of the ratio of TST to total time in bed (SE %).