In the Northern Hemisphere, we're entering the darkest stretch of the year. The days will keep getting shorter, until you might find yourself missing sunlight almost entirely during a 9-to-5 workday. That all turns around on the winter solstice, but it's still a long trek into spring. If all that darkness is getting you down, there are ways to help yourself, but understand your options before you make any purchases.
First things first, medical professionals have found that seasonal affective disorder may be overreported when self-diagnosed. Check with a doctor for a real run-down on whether your low energy and mood are body chemistry versus social and psychosomatic. Depression of any kind deserves treatment, so seek out professionals to get the best results.
The fix that may immediately come to mind is the light therapy box. It's built to emit a spectrum and intensity of light that imitates natural sunlight. Doctors recommend using it with supervision, or at least some guidance from a medical professional. It's best to establish a routine and sit by it for 20 to 30 minutes at the same time each morning. (Apparently it's a great way to take your coffee.) It's also recommended that you start in early fall, to ease yourself into the treatment as daylight becomes scarcer, but don't let that stop you if you're looking into it now.
One big caveat about light therapy is that you can overdo it. Not only can it affect your eyes and skin, but some users have also reported jitters of varying strength and duration after use. Finally, if you have bipolar disorder, light therapy may trigger manic phases, which is why it's especially important to consult a doctor first.
Since these specialized lamps aren't cheap — the top-rated option on Amazon usually runs $190 — you have other options for keeping your mood up. You can use cognitive behavioral therapy to reframe negative thoughts like "I hate winter" as more neutral statements like "I prefer summer over winter." And while nobody wants to hear it, maintaining an exercise routine even when it's dark and cold out can go a long way. Bundle up and take a short walk first thing in the morning, if you can. Your circadian rhythm and your cardiovascular system will thank you all day long.