Excluding Underlying Medical and Psychiatric Causes
Even though the DSM-5 criteria no longer differentiate between primary insomnia or insomnia caused by an underlying medical or psychiatric disorder, it remains imperative to assess for, and rule out, possible comorbid conditions that can be quite common. For example, 22% of individuals with insomnia also meet diagnostic criteria for a mood disorder. Because these conditions can cause or worsen insomnia, full remission is often impossible until they are identified and addressed.
In addition to pain, several common medical conditions seem to contribute to my patients' sleep difficulties.
Sleep apnea. One third of patients with insomnia have obstructive sleep apnea (OSA), which is caused by upper-airway collapse during sleep that leads to repeated breathing stoppages throughout the night. If a patient has OSA, their insomnia may be refractory to both nonmedication and medication treatment options. Once OSA is formally diagnosed with polysomnography and treated, the associated insomnia symptoms often completely resolve.
In addition to insomnia, there are also long-term risks associated with untreated OSA. These include an association with long-term cardiovascular and cerebrovascular disease.
The STOP BANG Inventory can help you quickly establish whether your patient is at high risk for OSA and would benefit from polysomnography. If they have five or more of the following factors, they are considered at high risk:
Observed that you stop breathing
History of high blood pressure
Body mass index > 35 kg/m2
Age older than 50 years
Neck circumference > 40 cm (15.75 in)
Although polysomnography is not part of the standard workup of insomnia, it is warranted in specific cases, such as when sleep apnea or another sleep disorder is suspected or if the insomnia remains refractory to treatment.
Restless legs syndrome (RLS). It is estimated that the prevalence rate for RLS in adults is as high as 15%, and it increases with age. RLS is characterized by the urge to move the legs, particularly at night, which causes difficulty sleeping. The cause of RLS is still being researched; however, there are medications that can significantly improve the symptoms and the negative impact on sleep.
Medication's impact on sleep. Caffeine and nicotine can negatively affect sleep. In addition, prescription medications used in the treatment of other medical and psychiatric conditions can worsen, and may even cause, insomnia. Therefore, it is important to review patient's medication lists and inquire about over-the-counter medications and use of supplements.
Common medications than can cause insomnia include anticonvulsants, beta-blockers, antipsychotics, antidepressants, and nonsteroidal anti-inflammatory drugs. A timeline may be useful to determine whether the initiation of a new medication, or a change in dose, correlates with worsening of insomnia.
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Cite this: Getting to the Source of Your Patients' Insomnia - Medscape - May 18, 2016.