Neuropharmacology of mental illness

The interplay of mental illness and sleep is multifaceted. Most psychiatric disorders produce sleep complaints. Behavioral health clinicians routinely inquire about a patient's sleep during diagnostic assessment and to monitor treatment response. Mental illness treatment that does not address sleep problems may lead to relapse. Persistence of insomnia is a negative prognostic sign, particularly for depression. Insomnia is the most common sleep complaint. Chronic insomnia is prevalent in about 10% of the United States' population. Only about one-fifth of these sufferers receive prescription hypnotics. Prescribing practices have changed in recent decades. From 1979 to 1999, survey data showed a decline in traditional hypnotics by 50%. Over that same span, the use of antidepressant drugs to treat insomnia increased more than two-fold [1]. Many people self-medicate for sleep problems. Over-the-counter remedies are primarily antihistaminic agents. Alcohol is also a common remedy, but, for reasons of limited efficacy and abuse potential, its use should be discouraged. Cognitive behavioral therapies, which are outside the scope of this chapter, are an effective alternative for many with chronic insomnia. The focus of this chapter will be on the prescription drugs used to treat psychiatric disorders that either have beneficial or adverse effects on sleep. Some of these drugs are commonly prescribed off-label for insomnia. Others produce insomnia, excessive daytime sleepiness, or parasomnias. Antidepressant therapies Current treatments for depression are largely based on concepts arising from monoamine oxidase inhibitor (MAOI) and tricyclic antidepressant (TCA) drugs discovered decades ago.