Winter hits different after the holidays are over, and there’s nothing between you and more sunshine but a couple of months of dreary cold.

Many people struggle to keep their spirits up during those weeks, especially, and if you’re one of them, here’s what you need to know about facing down seasonal affective disorder (SAD) again this year.

SAD is a subtype of recurrent major depressive disorder and also bipolar disorder, but is seen cyclically every year. The symptoms typically arise at particular times of the year (arriving in late fall or early winter) and last for 4-5 months.

Rare cases experience SAD in the summer, with symptoms starting the late spring and early summer.

Symptoms may not show up every year, and might be more severe some years than others, depending on other factors that influence mental health. The most common ones are persistent low mood, low energy level, difficulty concentrating, loss of interest and pleasure in hobbies, feeling guilty or hopeless, and irritability.

Winter SAD typically also sees oversleeping and overeating, while the summer pattern would experience the opposite.

The cause of the diagnosis isn’t clear, though most agree it likely has something to do with the changes in sunlight, which has a significant influence on our body’s clock. Circadian rhythm governs many of our body’s functions, and less exposure to sunlight in the winter could disrupt those enough that our mental health suffers.

Another theory is that people with SAD have altered levels of serotonin and melatonin, which influence both sleep and mood regulation. Sufferers show decreased levels of serotonin and increased production of melatonin, leading to the primary symptoms of fatigue and low mood.

Women are at higher risk for SAD, as are people who are already diagnosed with depression or bipolar disorder. People who live far from the equator are at higher risk, since daylight hours get shorter the farther you move away.

Treatment regimens include light therapy (exposing yourself to “sunlight” indoors), though according to many studies, there is at best mixed evidence that this is effective.

Though it may be effective in the short term, most of the studies had small sample sizes and other variables that could be corrected in larger-scope clinical trials.

Many doctors prefer to prescribe antidepressants, but it’s important to be proactive since they can often take 4-6 weeks to reach their full potential. Psychotherapy (talk therapy) can also help.

Other remedies for depression, like getting outside, eating right, and exercise can also help alleviate some of the symptoms.

If you’re feeling like these symptoms are hitting you hard, make sure you reach out – to a professional, a doctor, a friend, or even a prevention line.

We want you to be here when the sun comes out again.

If you thought that was interesting, you might like to read about why we should be worried about the leak in the bottom of the ocean.