Treatment of sleep dysfunction and psychiatric disorders.

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.