Most adults have experienced a period of sleeplessness or insomnia. In fact, as many of 30-50% of the general population may experience insomnia at one time or another. Insomnia is often described as a difficulty falling asleep or remaining asleep, and it is thought that particular chemicals in the brain are involved in regulating our sleep cycles.

The neurotransmitter serotonin (also known by the chemical name 5-Hydroxytryptamine, or the abbreviation 5-HT) has often been implicated in the regulation of sleep and wakefulness (being conscious). Neurons that produce serotonin are called serotonergic neurons; these neurons are active when we are awake, and less active, or inactive when we are asleep. There are many serotonin receptors; these receptors are grouped into seven subfamilies, based on their structures. Over the last 20+ years, research has demonstrated that a particular serotonin receptor (the 5-HT2A receptor) may play a role in treating insomnia.

A recent study published in the Journal of Pharmacology and Experimental Therapeutics reports that the drug, Nelotanserin, improved measures of sleep, such as sleep consolidation. “Sleep consolidation” can be thought of as an increase in the amount of time spent in “deep sleep,” and a decrease in the amount of time waking up (or a decrease in the number of “awakenings.”) Nelotanserin is a member of the class of drugs that act at the 5-HT 2A receptor. To date, the most commonly prescribed drugs to treat insomnia (Ambien, Sonata, Lunesta) are classified as non-benzodiazepine hypnotics, which act as GABA-A receptors, not as serotonin receptors. While there are not currently approved drugs that act like Nelotanserin to treat insomnia, there are two drugs that act similar to Nelotanserin, which are in late-stage clinical trials. These drugs are volinanerin and eplivanserin; like Nelotanserin, they offer a potential new strategy for treating insomnia.