Insomnia, classification

The International Classification of Sleep Disorders lists 88 types, with insomnia the most prominent symptom for many of these (17). Chronic insomnia is the most common sleep problem for which patients consult practitioners (18) and usually reflects psychological/ behavioral disturbances ( 19). Differences in treatment recommendations support the distinction between DSM-IV and the International Classification for Sleep Disorders ( 20). The DSM-IV divides primary disorders into two major groups the dyssomnias (in which the predominant disturbance is the amount, quality, or timing of sleep) and the parasomnias (in which the predominant disturbance is an abnormal event occurring during sleep) (7). 

Insomnia is a complaint, not a disease. The causes of insomnia are classified both in the DSM-IV for psychiatrists and in the International Classification of Sleep Disorders for sleep experts (Table 8—3). Insomnia can be a primary problem, or it can be secondary to medical or psychiatric disorders or to medications. Insomnia can also be due psychophysiological factors such as stress or to circadian rhythm distur-... 

Sleep disorders are common, and are generally underdiagnosed. The two major complaints related to sleep are insomnia ( I can t sleep ) and excessive daytime sleepiness (EDS, I can t stay awake ). EDS is a relatively nonspecific symptom. It can be the end result of any factor that causes sleep disruption, and it can be caused by primary or intrinsic sleep disorders. Insomnia of any cause can result in sleep deprivation and subsequent EDS. The most common cause of EDS in the general population is self-imposed sleep deprivation, or insufficient sleep syndrome. By contrast, the most common causes of EDS seen in a sleep center are primary (intrinsic) disorders of EDS. The American Academy of Sleep Medicine (AASM, formerly the American Sleep Disorders Association) classification of sleep disorders includes over 80 diagnoses that are associated with EDS, but the majority of patients evaluated at sleep centers have sleep apnea, narcolepsy, idiopathic hypersomnia, or periodic limb movements of sleep. 

Of the 88 sleep disorders listed in the International Classification of Sleep Disorders (12), the better-known and more prevalent disorders are the obstructive sleep apnea syndrome, insomnia, restless legs syndrome/periodic limb movement disorder, and narcolepsy (see also Chap. 5).These sleep disorders are common, and are known to interfere with the quality of sleep this chapter addresses the socioeconomic impact of these disorders. 

There are two major diagnostic manuals that provide classification systems for sleep disorders and define criteria for insomnia conditions the DSM-IV and the ICSD. Both manuals employ different terminology to label insomnia conditions, and present varying ways to define insomnia. 

Buysse DJ, Reynolds CF, Kupfer DJ, Thorpy MJ, Bixler E, Manfredi R, Kales A, Vgontzas A, Stepanski E, Roth T et al. (1994) Clinical diagnoses in 216 insomnia patients using the International Classification of Sleep Disorders, DSM-IV and ICD-10 categories A report from the APA/NIMH DSM-IV field trial. Sleep 17 630-637... 

According to ICD-10 [4], the sleep disturbance must have occurred at least three times per week for at least 1 month. The 1-month timeframe is essential also for primary insomnia in the American Psychiatric Association s DSM-IV classification [5], Also the patient must complain either of difficulty falling asleep or maintaining sleep, or of poor quality of sleep. However, the presence of the complaint of unsatisfactory sleep is not sufficient for the diagnosis of insomnia in its own right. It should also be a source of marked distress for the patient, and it should interfere with his/her ordinary activities in daily living. This prevents mistaking insomnia for just a symptom of another mental or physical disorder. 

The International Classification of Sleep Disorders [11] considers severity criteria as a guide to be applied in conjunction with consideration of the patient s clinical status. Mild insomnia refers to an almost nightly complaint of an insufficient amount of sleep or not feeling rested after the habitual sleep episode. There is little or no... 

Primary insomnia includes a number of insomnia diagnoses according to the International Classification of Sleep Disorders, including psychophysiological insomnia and idiopathic insomnia [11]. Psychophysiological insomnia most closely resembles primary insomnia. Individuals with idiopathic or childhood-onset insomnia show a lifelong inability to obtain adequate sleep there is no evidence of medical or psychiatric disorders that could account for the sleep disturbance. In sleep disor-... 

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