SAD Season is Coming: what you can do now to help with seasonal affective disorder.
9/25/2024 by Dr. Rachel Dillinger, MD PMH-C, integrative and reproductive psychiatrist
Are crumbling fall leaves outside accompanied by crumbling feelings inside? You’re definitely not alone. Seasonal Affective Disorder (SAD) is a condition that affects ~5% of adults in the United States, and even more in the northern U.S. (like here in Pennsylvania).
While typical depressive episodes can last several weeks to months, SAD episodes typically span late Fall through Spring–averaging 40% of the year. Sound like too large a chunk of life to just ride out? Read on for tips on identifying and addressing it!
What does SAD look and feel like?
It isn’t so different from typical depression (low energy, low mood, changes in sleep and appetite, less motivation, less joy in experiences and intimacy) with the important caveat that sleep tends to increase (“hypersomnolence”).
It might feel like getting out of bed in the morning is like moving through molasses, wanting to stay inside and not interact with others as much, a sense of dragging throughout the day, or like your “zest” for life is gone.
Who is more at risk for experiencing SAD?
Your risk increases:
1. The higher in latitude you are from the equator
2. If you were born with a uterus
3. The farther west you are within a given time zone
4. If you carry certain mutations for genes involved in our circadian rhythm (very much in the fledgling stage of research, but for the curious here is a 2023 study outlining the major candidates)
5. If you have a family history of SAD
6. If you are between the ages of 18 and 30 years old
What causes SAD?
While we don’t know for sure, most signs point toward changes in light exposure disrupting the circadian rhythm (our bodies natural sleep-wake cycle). The main players to think about when it comes to our circadian rhythm and SAD are a few chemicals found in our body called adenosine, serotonin, and melatonin.
Adenosine builds up in our cells throughout the day as a byproduct of using our energy source (flashback to middle school science class-ATP!). As it builds, it increases our sleep drive so we will be ready for bed at the end of the day. It also increases the amount of deep, restorative sleep we get.
Caffeine blocks adenosine receptors which is why it can make us feel less tired and more alert in the moment and then have a tough time falling asleep at night (and less restorative feeling sleep, to boot).
Serotonin not only helps build sleep drive throughout the day, but is also what gets broken down to make melatonin. Lower levels are associated with lower mood and experiencing insomnia.
Melatonin makes us feel overcome by the desire to sleep. It increases when it’s dark and decreases when it’s light (including currently as I type this on my laptop well after sunset). When levels are higher, it amplifies how sensitive our body is to the adenosine we built up during the day.
With longer exposure to daylight, we get more serotonin produced and more hours of the day with light suppressing melatonin release. That means a longer period of time without melatonin release increasing how tired we feel from that ever-building adenosine.
With shorter exposure to daylight, we get less serotonin produces and less suppression of melatonin release. That means feeling sleepier throughout the day, and for many, a low mood as well.
in darkness and decreases with light exposure.
What can be done about it?
Did you notice I said “exposure to daylight” and not “exposure to light”? One of the best things we can do is physically getting outside more, and aiming for sunlight exposure between the hours of 7-10AM. To supplement this, there are a number of bright light therapy lamps on the market today.
General guidelines include aiming for a brightness rating of 10,000 lux. For context, here is the lux rating of various situations:
1. Outside on a sunny day- 10,000 to 100,000+ lux
2. Outside on a cloudy or rainy day- 1,000 to 5,000 lux
3. Inside Target- 300-1000 lux
4. Typical kitchen- 300 to 700 lux
5. Typical living room- 100 to 300 lux
6. Typical bedroom- 100 to 200 lux
Getting outside in the winter, even on a cloudy day, beats even the brightest-bulbed big box store.
While sunlight exposure increases activated vitamin D levels, vitamin D as a treatment treatment has a weaker link for SAD. However, incorporating more into your diet or supplementing as needed is correlated with healthier balance of hormones and greater effectiveness of medications. It’s involved in over 300 chemical processes in the body so good to optimize this, especially when over 40% of us in the U.S. are deficient…
While therapy and medication can also help, I would highly recommend talking to your healthcare team about if these would be options to incorporate into your SAD plan for this year.