What is the treatment for a free-running circadian rhythm (FRCR) disorder, also known as Non-24-hour sleep-wake disorder?

From the Guidelines

Treatment for free-running circadian rhythm disorder should prioritize a combination of light therapy, melatonin supplementation, and behavioral modifications to help reset the body's internal clock and synchronize it with the environmental day-night cycle. When considering the most effective treatment approach, it is essential to focus on the most recent and highest quality study available, which in this case is the 2015 clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders by the American Academy of Sleep Medicine 1. According to this guideline, interventions for circadian rhythm sleep-wake disorders can be broadly categorized into prescribed timing of sleep-wake and/or physical activity/exercise, strategic receipt and/or avoidance of light, use of medications and/or supplements to phase shift and/or to promote sleep or wakefulness, and alternate interventions that exert effects by altering bodily functions to impact sleep/wake behaviors. Some key considerations for light therapy include:

• Timing of light exposure according to phase response curves (PRCs) to achieve the desired phase shift
• Intensity and duration of light exposure, with larger effects observed at greater intensities and longer durations
• The impact of prior light exposure or "light history" on the response to light therapy
• The strategic avoidance or reduction of light, particularly in the evening, to help regulate the circadian rhythm For melatonin supplementation, it is crucial to consider:
• The melatonin PRC, which is approximately 180 degrees out of phase with the light PRC
• The optimal dosing time, with dosing in the afternoon/evening shifting rhythms earlier and dosing in the morning shifting rhythms later
• The potential direct soporific effects of melatonin, particularly at higher doses In addition to light therapy and melatonin supplementation, behavioral modifications such as establishing a strict sleep-wake schedule, avoiding bright light exposure in the evening, and engaging in regular exercise during daylight hours can help strengthen circadian cues and promote a stable 24-hour rhythm. By combining these approaches and tailoring them to the individual's specific needs and circumstances, it is possible to effectively treat free-running circadian rhythm disorder and improve overall quality of life.

From the Research

Treatment Options for Free Running Circadian Rhythm

• Light therapy: timed exposure to bright light is often used in the treatment of circadian rhythm sleep disorders, including free-running type 2
• Melatonin: timed administration of melatonin, either alone or in combination with light therapy, has been shown to be useful in the treatment of free-running circadian rhythm sleep disorder 2, 3
• Melatonin receptor agonist: ramelteon, a melatonin receptor agonist, has been shown to be effective in treating free-running type circadian rhythm sleep disorder in sighted patients 4
• Vitamin B12: methylcobalamin, a form of vitamin B12, has been shown to enhance the phase-response of circadian melatonin rhythm to a single bright light exposure in humans 5
• Sleep hygiene education: education on sleep hygiene practices, such as maintaining a consistent sleep schedule and creating a sleep-conducive environment, can be beneficial in combination with other treatments 4

Therapeutic Applications

• Strategically timed light therapy and melatonin administration can help resynchronize the endogenous biological clock with the external light-dark cycle 2, 6
• Behavioral and pharmacological therapies, including melatonin agonists, can be used to manage circadian rhythm sleep-wake disorders 6
• Chronotherapies, such as bright light therapy and exogenous melatonin, can be used to restore circadian rhythm dysregulation 3