Institute for Continuing Education

Light, Sleep and Depression

Course Objectives

Upon successful completion of this module, you will be able to:

• Explain the modern environmental light deficiency, including quantitative measurement of light exposure using photopic lux, melanopic equivalent daylight illuminance (melanopic EDI), and other metrics relevant to circadian photoreception
• Identify and discuss evidence-based protocols for treating depressive disorders with bright light therapy, including optimal timing, intensity, duration, and wavelength parameters
• Explain the pathophysiology and clinical presentation of circadian rhythm sleep-wake disorders, specifically advanced sleep phase disorder (ASPD) and delayed sleep phase disorder (DSPD), and describe how appropriately timed light exposure can benefit patients with comorbid depression
• Analyze the neurobiological mechanisms underlying light therapy's antidepressant effects, including impacts on the circadian timing system, melatonin regulation, serotonergic neurotransmission, and sleep homeostasis
• Apply knowledge of circadian photobiology to develop appropriate light exposure recommendations for patients presenting with depression and circadian rhythm disorders in clinical sleep medicine practice

Course Information

People were designed to be outside. It is part of what makes us human. Perhaps somewhere back in evolution, our ancestors may have resembled monkeys or chimpanzees who climbed trees and lived in dark forests. For example, the “Gorillas In The Mist” lived in a gloomy rainforest. In contrast, as our ancestors became human, they moved out more into equatorial fields and savannahs, became able to run further, and started looking about further for food. Some seasons had clear bright sun every day and some had rain, but it was always bright near the equator where they lived. Much of the time, there was hardly even partial shade. Our modern human ancestors became intelligent in places which were indeed very sunny. It is for such a life that our bodies are adapted.