About C.E.T.

The Center for Environmental Therapeutics is 501(c)(3) nonprofit international organization of clinicians and scientists dedicated to promoting research and applications of chronotherapeutics for depression, sleep disorders, daytime fatigue, and associated illnesses.

Formed in 1994, the Center is most widely known for its website, which provides many free services for both the public, and professionals.

The most popular features are interactive self-assessment tools in 13 languages. More than a million people have used these tools to learn about their personal circadian rhythms, sleep, and mood, and to share this information with their doctors.

The online shop has something for both the public and professionals

Content developed for the public includes:

  • Ask Our Experts , a vast library of questions asked by other visitors, and their answers from team of experts

  • Latest Info & Guidance, prominent researchers and clinicians write for CET about the latest news from their research and clinical practice

  • Recommended Publications, suggestions range from a drug-free program to improve sleep, mood and energy to explanations of the circadian clock

CET also hosts opportunities and material for professionals, which include:

  • Clinical Assessment Tool Collection,, tools designed and produced by the Clinical Chronobiology and Biometrics Research groups at Columbia University/New York State Psychiatric Institute, useful in working with affective disorders and sleep problems

  • Colleagues’ Research, a respected group of clinicians and researchers write for CET.org on progress and directions in chronotherapeutics and allied sciences

  • Circadian Science and Chronotherapeutics, a curated collection of seminal papers and books gives an overview of major topics in the research, and application, of circadian science

These distinguished experts — our Board of Directors and Medical/Scientific Advisory Board — dedicate their efforts as volunteers.

CET's educational programs are funded primarily by sales commissions at its online shop and private donations.

Center for Environmental Therapeutics
info@cet.org