How daylight saving time impacts seasonal depression

CHICAGO (WLS) -- Daylight saving time ends overnight Saturday when clocks turn back an hour.

That means an extra hour of sleep.

But it also means it'll be darker earlier in the evening and that could impact people dealing with seasonal depression.

Doctor Dorothy Sit from Northwestern University Feinberg School of Medicine joined ABC7 to share more on how to deal with the time change.

Dr. Sit said light is an important cue for our body clocks. Behaviors and functions of the body such as sleep-wake patterns, digestion, physical activity, body temperature, stress responses and nightly release of melatonin (a natural hormone for sleep), all vary in accordance to daily or circadian rhythms that are highly responsive to light.

She said sleep experts generally understand that standard time is in closest alignment with our body's rhythms and adhering to standard time as long as possible (preferably year-round) is expected to produce positive health benefits.

The shorter, darker days related to the change in seasons to fall and winter, is linked to seasonal depression, Dr. Sit said, adding that the time change from daylight saving may certainly compound the seasonal symptoms.

A few signs of seasonal depression to look for include low mood, loss of interest or loss of enjoyment of their activities, decreased energy, excessive fatigue, increased sleep, heightened appetite and weight gain that onset in the fall or winter months and naturally resolve in the spring or summer are symptoms of seasonal or winter related depression.

Dr. Sit said people should watch for these symptoms and discuss treatment options with their physician or therapist especially if they feel unwell, unable to function.

Tips from the Sleep Foundation and the American Academy of Sleep Medicine suggest several things to better adjust to the time change:

Dr. Sit also said bright light therapy is the first treatment option for seasonal affective disorder, as well as a promising treatment option for other depressive disorders, namely non-seasonal major depression, depression in pregnancy and paired with a mood stabilizer (or antimanic agent) for bipolar depression. A dose of morning light (7,000 to 10,000 lx) for 30 min/d is advised for seasonal depression. With daily use, the SAD symptoms are expected to resolve completely by 2-3 weeks.