I’ve never been formally diagnosed with seasonal depression, also known as seasonal affective disorder (SAD). But as someone prone to bipolar depression, I have always noticed that my mood dips as the days get shorter, usually starting around my birthday in October (sad, I know!).

While I haven’t found the miracle cure for seasonal affective disorder, and I still rely on therapy and medications to get through the winter, there are a few things that make me less likely to experience seasonal depression.

First, what is seasonal depression?

Seasonal depression, also known as season affective disorder (SAD), is the tendency to have depressive symptoms in the winter, as days get shorter and exposure to natural sunlight decreases.

Experts believe that the decreased sunlight interrupts the body’s internal clock (aka the circadian rhythm) and may decrease the amount of serotonin in the brain.

Seasonal depression is more common at northern latitudes (think the Pacific Northwest or even cities like Fairbanks, Alaska, that see less than 4 hours of sunlight in the dead of winter).

But as someone who lives in San Diego, I can vouch that seasonal depression is just as real here in California.

When I worked a traditional 8 to 5 job, I usually had just enough time to get to work in the morning. When I got off in the evening, I walked to my car in darkness, with the parking lot dimly lit by street lights.

When I still squeezed in a workout (something that greatly helps my mood), it would be in a gym with artificial overhead lights.

Needless to say, this schedule of sitting inside for most of the daylight hours took a toll on my mental health every year.

So, how to combat seasonal depression?

These days, I mostly work from home and have a super flexible schedule, so getting enough sunlight is less of a challenge. I try to work by a window as much as possible, and my dogs make sure that I get outside regularly.

I also do my workouts outside in the morning, so that I can take advantage of the early morning sunshine, and I try to keep a consistent sleep schedule (although my fitness tracker says I’m not terribly successful at this last part).

But what about the years that I spent in Corporate America? Here are a few things that helped me, aside from therapy and the medications that I use year round:

Exercise

For several years, I was fortunate to work for a company that had its own weight room and showers as an employee benefit. I prioritized doing cardio after work at least 3 times a week.

While I’ve certainly benefited more from running outdoors, any exercise is going to increase your defenses against depression. Shoot for 30 minutes a day, if possible, but the important thing is just to do something regularly.

Light Box

Light boxes emit light for therapeutic use. They can come in different wavelengths, including full spectrum, blue, and red. Each wavelength has a slightly different effect.

I personally used the HappyLight by Verilux when I worked in an office. I kept the small box on my desk and turned it on for about 30 minutes while I was checking work emails.

I did get a lot of questions from my coworkers (the light box was super bright), but I noticed that after several weeks, I did in fact experience a slight boost in mood.

I have thought about using a light box even now that I work at home. HOWEVER, I have since learned that light boxes and other forms of light therapy can cause mania in people with bipolar.

I never experienced this personally, but out of caution I decided to trade my light box for natural sunlight exposure now that my days are more flexible.

Vitamin D

Some studies have shown that people with recurrent seasonal depression are more likely to be deficient in Vitamin D. This vitamin, as you may remember, is naturally produced by the body as a result of sun exposure.

Last winter, I really struggled with depression-like physical symptoms—lethargy, fatigue, etc. After several months of this, my psychiatrist did a blood panel. Sure enough, I was deficient in vitamin D.

I started supplementing vitamin D right away, and within a few weeks I noticed a huge improvement in my energy levels. I didn’t take vitamin D over the summer (I would consult your doctor), but I added it back into my routine this month.

Start planning for seasonal depression now

I’ve been through seasonal depression enough times now that I know to plan ahead for this winter.

Rather than wait for depression to kick in, I’m increasing my physical activity (easier for me when it’s cooler), supplementing vitamin D, and working on sleep consistency.

We recently moved, so I also made sure to put my desk by a window, although most days I’ve been working on the patio.

Will I experience a dip in my mood this winter? Probably. But hopefully it won’t be as severe as last year, and I’ll be able to deal with it more proactively.

I may not be using my light box anymore, but I’ve learned that sunlight is my brain’s best friend, and I will make sure I get as much of it as I can, even when San Diego’s daylight hours are cut short.