September 15, 2011

Sleep disturbances can have multiple causes. These can be organized into two broad areas, as primary sleep disturbances and secondary sleep disturbances. Primary sleep disturbances usually imply primary neurological sleep disorders, such as disordered breathing/breathlessness during sleep (sleep apnea), restless leg syndrome, and conditions of abnormal daytime sleepiness/”sleep attacks” (cataplexy and narcolepsy). Patients with sleep apnea may have significant daytime sleepiness as well as sleep disturbance. Sleep apnea may be both central (due to brain/central nervous system causes), obstructive (due to lung/airway causes), or mixed (both central nervous system and airway) disorders. The obstructive form of sleep apnea, which represents an anatomical obstructive process to the airways, has relatively good outcome compared to a central form of apnea. Treatment outcomes in these sleep disorders are directed to improving quality of sleep at proscribed times and optimizing the benefits of quality sleep. Treatment should primarily be driven by diagnosis rather than symptom-driven, which is often the mistake that results in compromised patient care. Patients presenting with primary neurological disorders causing insomnia need to have these entities identified with an appropriate workup which may involve a sleep lab evaluation. Treatment would be driven by the resulting diagnosis and treatments specific to the underlying disorder.

The broader and more common presentations of insomnia are due to other medical or psychiatric causes (secondary presentations). Medical causes of insomnia would be due to neurological disorders as well but not primary sleep disorders as described previously. Delirium (a medical disorder of disturbed consciousness/ alertness) may result from primary neurological disorders or other medical problems (such as brain infection) that can impair brain function. Primary neurological diseases that can cause delirium include tumors, brain injury from many causes including stroke or bleeding (hemorrhage), and seizure disorders. Appropriate identification and treatment of these disorders with timely intervention are critical. Headache may present as a symptom and may occasionally indicate a serious process that needs to be identified and treated. Medical processes that impinge on the brain can cause delirious states or milder brain compromise. For example, a person with brain disease and compromised function from a dementia may have a urinary tract infection, which results in significant agitation and sleep disturbance. A person with a relatively intact brain but significant medical compromise such as significant untreated heart failure might find themselves unable to sleep. In each example, insomnia should not be treated with a sedative but rather by managing the acute medical problem.

Assuming that an individual’s medical and neurological issues are not the cause of the sleep disturbance, then psychiatric illness could be the one contributing. Psychiatric disorders have many potential issues that need to be addressed. The mood disorders including depression and mania can have sleep disturbance as one of their principal symptoms. When this is not recognized, inappropriate interventions can lead to eXacerbation of the illness, which often leads to further sleep disturbance. Even when the mood disorder is recognized, if the disorder is not well understood and managed, interventions can eXacerbate the disorder and the sleep disturbance. Sleep disturbances occur in schizophrenia and anXiety disorders as well. When these disorders are not appropriately managed, the condition of the affected person can be significantly compromised. Sometimes, an individual with psychiatric illness and insomnia is in denial about the underlying illness and he or she may be unwilling to cooperate with appropriate treatment. In some cases, there are complaints of anXiety that are based on untreated psychotic illness. Interventions with sedative/anXiolytics can lead to complicating or compounding the illness of that person without fundamentally improving the condition. In a person with a dementing illness, insomnia as a sleep disturbance occurs. If the cause of the disturbance is not properly identified, then the course of that person’s presentation may be significantly worsened.

Finally, there are persons who are relatively healthy but because of an acute stressor can eXperience a short-term symptom of insomnia. Such cases, in the absence of other issues, may be treated by sedative hypnotics provided they are limited to short-term use.

Further, stresses and maladaptive sleeping regimens often develop in a significant portion of the population. Sleep hygiene is an important ingredient in treatment. When insomnia occurs as in any other human symptom, there needs to be an understanding of the underlying causes that will determine the most efficacious intervention.

SEE ALSO: Mood disorders, Sleep disorders, Sleep hygiene

Suggested Reading

  • Cartwright, R. (1999). Sleep disorders: Diagnosis and treatment. American Journal of Psychiatry, 156, 493.
  • Nowell, P. D., Buysse, D. J., Reynolds, C. F., III, et al. (1997). Clinical factors contributing to the differential diagnosis of primary insomnia related to mental disorders. American Journal of Psychiatry, 154, 1412-1416.
  • Schnierow, B. J. (2000). The enchanted world of sleep. American Journal of Psychiatry, 157, 1190a-1191a.


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