Department of Animal Science Hoffmann Lab

Interviews with Dr. Hoffmann on the topic of seasonal affective disorder (SAD) aka winter depression

Video interview about seasonal depression for NewsPoint360 on YouTube.

Written articles bout SAD and daylight savings

Light Therapy Lamps: What's The Difference Between Cheap And Expensive Ones?

Seasonal affective disorder: Why some feel sluggish and sad during winter time

How to Cope With Seasonal Depression During the COVID-19 Pandemic

Daylight Saving Time: ‘Falling Back’ Can Increase Seasonal Depression 

Ask the expert: Light, seasonal affective disorder and COVID-19

Will Seasonal Affective Disorder Be Worse This Year Because of COVID-19

Light can also impact mood and energy in the summer

You Can Get SAD In the Summer, Too

Light treatment for winter depression and loss of energy in the winter

Seasonal affective disorder (SAD) also commonly known as seasonal depression can be prevented with light treatment. Although both men and women experience SAD, 4x more women are affected.

If you think you might be at risk of SAD (or lack of energy and reduced motivation in the winter) therapeutic light treatment will most likely benefit you and prevent or reverse SAD.

To prevent SAD: start light treatment BEFORE you start experiencing loss of energy and loss of interest. 

To reverse SAD: start light treatment as soon as possible. The benefit of light treatment will take days to weeks to happen, so be patient.

 Light box instructions (“Happy light”)

• Use daily if possible, but at least 5 days per week.
• Use early after waking, preferably 7-8AM and/or mid-day. These are the times of the day where you are most sensitive to the light, so you will get the greatest benefit, and can spend less time in front of the light box.
• Most importantly get some light. If 10AM-noon is optimal for you, that’s fine.
• You do not need to use the light box at the same time of the day every day.
• Avoid extensive use in the late afternoon.
• Do not use in the evening/after sunset. In the evening you want to avoid bright light to promote endogenous melatonin release.
• Use the lightbox at least 1-1.5h per day. This can be broken down into 2-3 sittings. You can use it less if you use it in the morning soon after wakeup (30-45 min in the morning at 7-8AM is enough). 

Light box alternatives that can be combined with light box treatment

• +1h outdoor walks in the AM. Works best if you walk in the sun. Even on a cloudy day natural light will be efficient in preventing SAD, you will just need a longer walk.
• Evening melatonin. Melatonin is purchased over the counter. Take 0.5 mg around 5PM.
• Melatonin can also help you get over jet lag faster, it should be taken a couple of days before you go on your trip at ~1h before the desired bedtime on the new time zone. For example, if you are doing a trip where you will have a 6h jet-lag and you have to get up 6h earlier (like going to Europe from New York), this is what you do:
  • Desired bedtime is 10PM, then…
  • 3-4 days before you leave take melatonin a 3PM.
  • When you arrive on the new time zone, take melatonin at 9PM (1h before you go to bed). You can take melatonin for 3-10 days, or until you feel completely adjusted to the new time-zone.

Recommendations for light boxes (“happy lights”)

These are some general recommendations, and many different light boxes exist. The important criteria is bright intensity (light brightness is measured in Lux).

Light box criteria and placement

• 10,000 lux at ≥12 in from your eyes/face.
• Some of the more expensive light box models will allow you to be further away from the light box, like 24 in and you will still experience 10,000 lux.
• White or blue light. There is no clear advantage of blue light (blue light wavelengths), although blue-enriched light may not have to be as bright (= lower lux).
• UV filter. This will avoid risk of retinal damage.
• Do not look straight into the light box. For example, put it at an angle next to your computer screen, place it on the table next to where you are reading a book. If you love cooking, hang it on the wall in the part of the kitchen where you spend the most time.