Patients with
neurologic disorders commonly experience sleep dysfunction and
psychiatric disorders. The most common sleep dysfunction is
insomnia, which is a primary symptom in 30% to 90% of
psychiatric disorders.
Insomnia and
fatigue are prominent symptoms of
anxiety disorders and major depression, including patients who are treated but have residual symptoms. Anxiety and
depressive disorders account for 40% to 50% of all cases of
chronic insomnia. It is also recognized that
primary insomnia and other primary
sleep disorders produce symptoms that are similar to those reported by patients with
psychiatric disorders. A clinician must judge whether
sleep deprivation causes mood disturbance or whether depressive or
anxiety disorder represents the primary reason for sleep dysfunction. When
insomnia is comorbid with mild to moderate depression,
therapy should begin with bedtime dosing of sedating
antidepressants such as
mirtazapine,
nefazodone, or
tricyclic antidepressants, which are preferred because of their
sedative effects, although side effects may limit their usefulness. Intervention for
chronic insomnia is similar in nonpsychiatric and psychiatric patients. Behavioral
therapies, particularly cognitive behavioral therapy, and lifestyle changes show significant long-term efficacy as treatments for
chronic insomnia.
Sedative hypnotic agents are the most studied agents to treat
insomnia, particularly those that are active through the
benzodiazepine receptor-
GABA complex, such as
benzodiazepines,
eszopiclone,
zaleplon, and
zolpidem. The new
melatonin-receptor agonist
ramelteon has not yet been studied in psychiatric patients. Prescription of adjunctive
trazodone 50 to 150 mg is a common clinical practice to treat comorbid
insomnia during
antidepressant therapy, but published data are surprisingly limited when considered against the frequent usage of
trazodone. Although there has been insufficient research on the use of atypical
antipsychotic agents in severe
insomnia, psychiatrists use
quetiapine,
olanzapine, or other agents to lessen agitation that disrupts sleep onset or maintenance. When
insomnia or
hypersomnia continues even as mood, anxiety, or thought disorders improve with standard
therapy, the physician should consider the potential presence of underlying
sleep disorders.