780.xx Sleep Disorder Due to a General Medical Condition

Diagnostic Features

The essential feature of Sleep Disorder Due to a General Medical Condition is a prominent disturbance in sleep that is severe enough to warrant independent clinical attention (Criterion A) and is due to a general medical condition. Symptoms may include insomnia, hypersomnia, a Parasomnia, or some combination of these. There must be evidence from the history, physical examination, or laboratory findings that the sleep disturbance is the direct physiological consequence of a general medical condition (Criterion B). The disturbance is not better accounted for by another mental disorder, such as Adjustment Disorder, in which the stressor is a serious general medical condition (Criterion C). The diagnosis is not made if the sleep disturbance occurs only during the course of a delirium (Criterion D). By convention, sleep disturbances due to a Sleep-Related Breathing Disorder (e.g., sleep apnea) or to Narcolepsy are not included in this category (Criterion E). The sleep symptoms must cause clinically significant distress or impairment in social, occupational, or other important areas of functioning (Criterion F).

In determining whether the sleep disturbance is due to a general medical condition, the clinician must first establish the presence of a general medical condition. Further, the clinician must establish that the sleep disturbance is etiologically related to the general medical condition through a physiological mechanism. A careful and comprehensive assessment of multiple factors is necessary to make this judgment. Although there are no infallible guidelines for determining whether the relationship between the sleep disturbance and the general medical condition is etiological, several considerations provide some guidance in this area. One consideration is the presence of a temporal association between the onset, exacerbation, or remission of the general medical condition and that of the sleep disturbance. A second consideration is the presence of features that are atypical of primary Sleep Disorders (e.g., atypical age at onset or course or absence of family history). Evidence from the literature that suggests that there can be a direct association between the general medical condition in question and the development of a sleep disturbance can provide a useful context in the assessment of a particular situation. In addition, the clinician must also judge that the disturbance is not better accounted for by a primary Sleep Disorder, a Substance-Induced Sleep Disorder, or other primary mental disorders (e.g., Adjustment Disorder). This determination is explained in greater detail in the “Mental Disorders Due to a General Medical Condition” section.

Subtypes

The subtypes listed below can be used to indicate which of the following symptom presentations predominates. The clinical presentation of the specific Sleep Disorder Due to a General Medical Condition may resemble that of the analogous primary Sleep Disorder. However, the full criteria for the analogous primary Sleep Disorder do not need to be met to assign a diagnosis of Sleep Disorder Due to a General Medical Condition.

Insomnia Type. This subtype refers to a sleep complaint characterized primarily by difficulty falling asleep, difficulty maintaining sleep, or a feeling of nonrestorative sleep.

Hypersomnia Type. This subtype is used when the predominant complaint is one of excessively long nocturnal sleep or of excessive sleepiness during waking hours.

Parasomnia Type. This subtype refers to a sleep disturbance characterized primarily by abnormal behavioral events that occur in association with sleep or sleep transitions.

Mixed Type. This subtype should be used to designate a sleep problem due to a general medical condition characterized by multiple sleep symptoms but no symptom clearly predominates.

Recording Procedures

In recording the diagnosis of Sleep Disorder Due to a General Medical Condition, the clinician should note both the specific phenomenology of the disturbance, including the appropriate subtype, and the specific general medical condition judged to be causing the disturbance on Axis I (e.g., 780.52 Sleep Disorder Due to Thyrotoxicosis, Insomnia Type). The ICD-9-CM code for the general medical condition should also be noted on Axis III (e.g., 242.9 thyrotoxicosis). (See Appendix G for a list of selected ICD-9-CM diagnostic codes for general medical conditions.)

Associated Features and Disorders

Associated laboratory findings. Laboratory findings are consistent with the underlying general medical condition. There are no polysomnographic findings that are specific to the entire group of Sleep Disorders Due to a General Medical Condition. Most general medical conditions cause a decrease in total sleep duration, an increase in awakenings, a decrease in slow-wave sleep, and (less consistently) a decrease in rapid eye movement (REM) sleep or phasic REM density. Some medical conditions produce more specific polysomnographic findings. For example, individuals with fibromyalgia syndrome complain of nonrestorative sleep and often have a distinct pattern of alpha EEG activity during non-rapid eye movement (NREM) sleep. Sleep-related seizures result in specific EEG discharges that are consistent with the underlying seizure type.

Associated physical examination findings and general medical conditions. Individuals with a Sleep Disorder Due to a General Medical Condition are expected to have the typical physical findings of the underlying general medical condition. Sleep disturbances may result from a variety of general medical and neurological conditions including (but not limited to) degenerative neurological illnesses (e.g., Parkinson’s disease, Huntington’s disease), cerebrovascular disease (e.g., insomnia following vascular lesions to the upper brain stem), endocrine conditions (e.g., hypo- or hyperthyroidism, hypo- or hyperadrenocorticism), viral and bacterial infections (e.g., hypersomnia related to viral encephalitis), coughing related to pulmonary disease other than sleep-related breathing conditions (e.g., chronic bronchitis), and pain from musculoskeletal disease (e.g., rheumatoid arthritis, fibromyalgia). General medical conditions in which hypersomnia may present as a core feature of the illness include myotonic dystrophy and Prader-Willi syndrome.

Differential Diagnosis

Sleep disturbances are extremely common in the context of a delirium; therefore, a separate diagnosis of Sleep Disorder Due to a General Medical Condition is not given if the disturbance occurs exclusively during the course of the delirium. In contrast, a diagnosis of Sleep Disorder Due to a General Medical Condition may be given in addition to a diagnosis of dementia if the sleep disturbance is a direct etiological consequence of the pathological process causing the dementia and the sleep disturbance is a prominent part of the clinical presentation.

Sleep Disorder Due to a General Medical Condition must be differentiated from expected disruptions in sleep patterns, primary Sleep Disorders, Sleep Disorders Related to Another Mental Disorder, and Substance-Induced Sleep Disorders. Many individuals experience sleep disruption during the course of a general medical or neurological condition. In the majority of cases, such complaints do not merit an additional diagnosis of a Sleep Disorder. Rather, a diagnosis of Sleep Disorder Due to a General Medical Condition should be reserved for cases in which the sleep disturbance is a very prominent clinical feature, atypical symptoms are present, or the individual is sufficiently distressed by the sleep symptom or attendant impairment that specific treatment for this disturbance is required.

Sleep Disorders Due to a General Medical Condition are characterized by symptoms similar to those in primary Sleep Disorders. The differential diagnosis rests not on specific symptoms but rather on the presence or absence of a medical condition judged to be etiologically related to the sleep complaint. In the specific cases of Narcolepsy and Breathing-Related Sleep Disorder, the underlying etiology of the sleep disturbance is assumed to be a general medical condition. However, in these two specific examples, the general medical condition does not exist independent of sleep symptoms. For this reason, these two disorders are included in the “Primary Sleep Disorders” section.

Differentiating a Sleep Disorder Due to a General Medical Condition from Substance-Induced Sleep Disorder can prove very difficult. In many cases, individuals with a significant general medical condition often take medication for that condition; these medications in turn may cause sleep-related symptoms. For example, an individual may have sleep disruption related to asthma. However, that individual may also be treated with theophylline preparations, which in some cases can themselves cause sleep disturbance. Differentiating a Sleep Disorder Due to a General Medical Condition from a Substance-Induced Sleep Disorder often rests on chronology, response to treatment or discontinuation of medications, and longitudinal course. In some cases, concurrent diagnoses of Sleep Disorder Due to a General Medical Condition and Substance-Induced Sleep Disorder may be appropriate. In cases in which a drug of abuse is suspected to be the cause for the Sleep Disorder, a urine or blood drug screen may help to differentiate this problem from a Sleep Disorder Due to a General Medical Condition.

If the clinician cannot determine whether the sleep disturbance is primary, related to another mental disorder, due to a general medical condition, or substance induced, the appropriate diagnosis is Dyssomnia or Parasomnia Not Otherwise Specified.

Relationship to the International Classification of Sleep Disorders

The International Classification of Sleep Disorders (ICSD) contains the general section “Medical/Psychiatric Sleep Disorders.” Specific diagnoses are presented for Sleep Disorders that are associated with neurological disorders (with 7 examples listed) and Sleep Disorders that are associated with other medical disorders (with 7 examples listed). Although only 14 medical/neurological disorders are specifically cited in the ICSD, the clinician may diagnose a Sleep Disorder associated with any other medical disorder simply by using the appropriate ICD-9-CM codes.

Diagnostic criteria for 780.xx Sleep Disorder Due to . . . [Indicate the General Medical Condition]

A. A prominent disturbance in sleep that is sufficiently severe to warrant independent clinical attention.
B. There is evidence from the history, physical examination, or laboratory findings that the sleep disturbance is the direct physiological consequence of a general medical condition.
C. The disturbance is not better accounted for by another mental disorder (e.g., an Adjustment Disorder in which the stressor is a serious medical illness).
D. The disturbance does not occur exclusively during the course of a delirium.
E. The disturbance does not meet the criteria for Breathing-Related Sleep Disorder or Narcolepsy.
F. The sleep disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.

Specify type:

.52 Insomnia Type: if the predominant sleep disturbance is insomnia

.54 Hypersomnia Type: if the predominant sleep disturbance is hypersomnia

.59 Parasomnia Type: if the predominant sleep disturbance is a Parasomnia

.59 Mixed Type: if more than one sleep disturbance is present and none predominates

Coding note: Include the name of the general medical condition on Axis I, e.g., 780.52 Sleep Disorder Due to Chronic Obstructive Pulmonary Disease, Insomnia Type; also code the general medical condition on Axis III (see Appendix G for codes).