Insomnia, Primary

The purpose of this study was to understand the effectiveness of intermittent hypoxia in the treatment of primary insomnia.

Individuals who have insomnia with short sleep duration (ISS) differ from individuals who have insomnia with normal sleep duration (INS) in terms of health risks (i.e., hypertension) and treatment response. This study will examine whether patients with ISS and INS demonstrate a differential response to two common insomnia treatments. One is behavioral, Cognitive Behavioral Therapy for Insomnia (CBT-I). The other is a widely prescribed, non-habit-forming medication, trazodone used at a low dose. The investigators' findings could lead to evidence-based treatment guidelines that help clinicians more effectively match treatments to insomnia patients and reduce associated health problems.

This study evaluates two behavioral treatments for patients with insomnia disorder: Bedtime Restriction Therapy (BRT) and Cognitive Behavioral Therapy for Insomnia (CBT-I). Both therapies aim to improve the clinical symptomatology of insomnia by teaching participants techniques to better manage their sleep schedule and habits. BRT is a simpler and shorter therapy focused on aligning the time spent in bed with reported sleep time. CBT-I includes additional components such as relaxation techniques and cognitive exercises. The study will compare these treatments to see if BRT is as effective as CBT-I in improving the clinical symptomatology of insomnia.

Insomnia is generally believed to be caused by excessive arousal of the brain and body. Rather than transitioning normally and quickly from wakefulness to sleep, individuals with insomnia tend to enter into a self-perpetuating cycle of self-referential thought and arousal. Brain imaging research has shown that these same internally focused self-reflective thoughts tend to activate a core system in the brain known as the Default Mode Network (DMN). The DMN is usually active when a person is internally focused, such as during daydreaming or mind wandering, but tends to be deactivated when the brain is focused on the external environment. The investigators hypothesize that excess activation and connectivity of this brain network may perpetuate internal conversations, worry, and rumination, preventing individuals with insomnia from falling asleep quickly and remaining asleep. Therefore, the goal of the present study is to use a brain stimulation technique known as transcranial magnetic stimulation (TMS) to target the DMN and slightly reduce its activation before bed. This should result in an easier time falling asleep. For this study, the investigators will recruit 20 healthy individuals and have them sleep in the lab on two occasions. On one occasion, they will be stimulated with a type of TMS called continuous theta burst stimulation (cTBS), which will be targeted toward their DMN. They will then try to sleep in the lab while the investigators record their brain waves using a technique known as polysomnography (PSG). On the other occasion, these same individuals will undergo the same procedure, but the TMS machine will be in a deactivated mode to present a "sham" stimulation. Participants will again try to sleep in the lab following the sham treatment while being recorded with PSG. Neither the participants nor the experimenters will know which condition the participant is receiving at the time. This will only be revealed later. Additionally, all participants will receive a brain scan just before and just after the TMS procedures so that the investigators can examine changes in brain connectivity and chemistry. The investigators expect that the participants will sleep better following the cTBS than following the sham condition and that this will be associated with measurable differences in their brain connectivity and brain chemistry. If effective, this project would have identified an innovative and novel approach for improving sleep without using drugs.