Michael Terman Ph.D.

Chronotherapy

Sunrise When You Need It

New technology can fool the clock on the wall and help your inner clock.

Posted Oct 28, 2013

Our species spent most of its evolutionary history in equatorial regions, where dawn and dusk came gradually at much the same time all year around. Countless centuries later, our brain is still geared to expect a similar daily pattern of light and darkness, even though we have largely migrated to latitudes where the days are longer in summer and shorter in winter. This displaced position on earth still overwhelms the influence of man-made interferences: streetlights, room lights, and late-night TV and computer light. Human migratory patterns have produced predictable but often unrecognized effects on our mood, energy, and sleep.

One such effect presses on us now as we move toward winter. Winter blues and its more severe relative, seasonal affective disorder (SAD), are marching in. The symptoms of SAD—gloom and despair, excessive sleep, food cravings, pervasive anxiety, among others—add up to a major depression. Yet there is one big difference from unpredictable depressions: its timing, with the clear link to light deprivation in winter. Getting too little light, or getting enough but not at the right point in the day, puts you at risk for up to half a year of relative agony.

Fortunately, the cause implies a cure. Getting enough light, and at the right time, offers a way of dealing with the problems created by light deprivation. By restructuring the amount and pattern of our daily light exposure, we can achieve remarkable therapeutic results, even in cases of severe depression or sleep disorders. Best of all, the intervention is environmental, not pharmaceutical. The most widely known method is bright light therapy. This involves sitting in front of a therapeutic light box of a particular brightness, for a particular length of time, at a specific time of day (usually in the early morning). Each user needs to experiment at the start to find his or her optimum settings.

The therapeutic technology is evolving, bringing the light signal more toward the equatorial ideal. Of course, daylight and nighttime do not turn on and off with the flick of a switch. Rather, the eyes and brain received the signals gradually, at levels well below full daylight.

Terman under a light diffuser with summer/winter dawns.

Michael under a broad light diffuser, with graphs of simulated summer and winter dawns.

3-D graph of dawns and dusks throught the year

Dawns and dusks throughout the year, halfway between the equator and the north pole.

Meanwhile, entrepreneurs have jumped on the dawn simulation wagon, without paying attention to the need for research and verification. You can easily buy a “dawn alarm clock,” with built-in lights that gradually get brighter over some preset length of time, usually shorter than any sunrise on earth. Some of these even come with radios, MP3 players, and built in bird sounds, not to mention aromatherapy. If you like the idea of being awakened gradually by a bedside lamp that plays music, smells like spruce or lavender, and trills like a lark, you might enjoy using one of these gadgets. But you should not expect to get the same results that bright light therapy or clinical dawn simulation offer. For that, you’ll need equipment and an approach that has been tried and validated in clinical research. You can learn more from the recommendations in our book or at our website.

Michael and Ian are co-authors of the 2013 Penguin paperback, Reset Your Inner Clock. They invite you to follow them on Twitter for news updates, opinions, and challenging Q-and-A’s. If you want to stay on top of body-clock matters, light therapy, and more — and take advantage of confidential, online self-assessments of inner clock time, depression, and seasonality — you should become part of the nonprofit Center for Environmental Therapeutics community. Email PTuser@cet.org so we can stay in contact.