About Gideon

Dr Gideon Dunster is a project manger at the Allen Institute for Cell Science in Seattle. As a project manager, Gideon works with all kinds of different teams to help accomplish the goals of the Institute more smoothly and efficiently. Growing up in northeastern Ohio, Gideon was very active: he played sports, he sang and played in the orchestra, he was on the Science Olympiad team, and was in the school plays and musicals. When he went to college, he wasn’t sure what he wanted to do so he spent the first two years taking classes in everything from Theater and Philosophy to French and Psychology. Eventually he decided that he really wanted to be a Biology professor, so he began working towards graduate school. After spending time in a post-doctoral position, he realized that while he loved doing research and teaching, he wanted to work in a big team environment where he could help others work on big, unique scientific questions. When Gideon’s not working, he likes biking, reading, and spending time with friends.

Human beings have a strong circadian system that helps them time many biological functions throughout the day and night. These functions can include things like when to sleep or when certain hormones are released, among many others. This circadian system is very sensitive to light, like sunrise and sunset, to help “set” our internal biological clock to the external environment. However, that system also responds to artificial light, which can cause our biological clock to become out of sync with the natural environment. Artificial light at night (ALAN), light that comes from streetlamps and cars and light up signs, is one source of light that has the potential to cause our circadian clocks to get out of sync with the environment. When that happens, it’s possible that there is a greater risk for people to develop mental health disorders like anxiety or depression.

A couple years ago, Gideon and a team of colleagues released the results of a study that explored the affect that outdoor artificial lights at night have on sleep and mental health disorders in US adolescents (ages 13-18). There is significant research around the how indoor artificial lights (like phone, laptop, or TV screens) have on these things, but less was known about outdoor light. To investigate these questions, Gideon and his team sent out a survey to thousands of families (representing over 10,000 teens) and asked a variety of questions ranging from demographic information (age, race, sex, family income, etc.) to questions about sleep patterns and mental health events in the past year. To get measurements of ALAN, the researchers collected satellite data.

One of their first steps was to determine if certain demographic groups were exposed to more ALAN than others. They found, for example, that there wasn't a significant difference between the amount of ALAN that was experienced by males vs females, but there was a difference between teens who lived in non urban areas (outside the city) and those who lived in metropolitan areas (big cities) where there are typically more streetlights, cars, etc. They also found that ALAN exposure was higher in non-white teens, those who come from immigrant backgrounds, and those with lower family incomes.

Their next step was to determine how much sleep teens got (across all demographics) based on how much ALAN they were exposed to. They found that ALAN exposure had more of an impact on weeknight sleep than weekend sleep. The teens exposed to the least amount of ALAN got the most weeknight sleep (primarily because they went to sleep earlier), and those who were exposed to the most ALAN slept the least on weeknights (due to later bedtimes). Finally, they looked for patterns between ALAN exposure and recent history of a mental health disorder. They found that higher ALAN exposure was linked to a higher likelihood of a mood or anxiety disorder in the past year, as well as bipolar disorder and some phobias.

Taken together, this study shows that exposure to ALAN does appear to have a relationship with both how teens are sleeping and their mental health. More ALAN led to later bedtimes and less sleep on the weekdays. In addition, greater exposure to ALAN was associated with a greater odds for certain mental health disorders. Together, it looks like the amount of light that we use in our society may be having a negative impact on our daily lives. It is especially important to note that these negative impacts may be more pronounced in some racial, immigrant, and socioeconomic groups. This is important to know about, because everybody deserves a good night's sleep and good mental and physical health.