‘Tis the season for yuletide carolers, delicious feasts, and, of course, holiday depression. Known in the medical world as seasonal affective disorder (SAD), holiday depression may be more common than you think. More than 6 percent of Americans are affected by the disorder, and another 14 percent are affected by “winter blues.” 

The disorder can be triggered by many things, from gloomier, shorter days to knowing that your to-do list is as long as Santa’s. 

And while the last place you may think of turning to for advice is a 30-minute Christmas short, Charles M. Schulz’s 1965 “A Charlie Brown Christmas” actually offers some practical guidance.

Here are four lessons from the beloved Charlie Brown and Lucy that are sure to make your spirits merry and bright this season.

Lucy was right: Getting involved is one of the simplest ways of spreading holiday cheer. Research shows that volunteering can help increase self-confidence, provide a sense of purpose, and beat depression.

Remember that getting involved doesn’t have to be complicated — there’s no need to volunteer to be the neighborhood Christmas play director like Charlie Brown!

Perhaps it’s spending an hour helping out at a soup kitchen or volunteering to wrap gifts at the mall. Whatever you decide, make sure it’s something you enjoy doing.

From going to your child’s school pageant to attending your work’s office party to traveling to grandma’s house for the annual family potluck, the holidays are one of the busiest times of the year.

And while setting aside time for yourself may seem as unlikely as Charlie Brown picking the perfect Christmas tree, it’s key to holiday happiness. Don’t feel like you have to attend every cookie exchange party or every tree lighting ceremony. Pick the social events you’re most interested in and pencil them in on your calendar. If something else pops up, erase another event off your list.

Even if you spent hours browsing for the perfect gift for your loved one on Amazon or vying with other crazed shoppers at the mall, the fact is that your ideal gift probably isn’t going to be under the tree.

A study has found that almost 1 out of every 7 adults will return a gift within the following two weeks of Christmas. On top of that, more than 49 million people admitted receiving an awful gift. 

But, as you’ve heard before, it’s not really about what the gift is, but rather the thought that went into it. Taking a moment to write a thank you note can actually boost your own mood — even if it’s for another pair of reindeer socks.

The average American plans to spend about $830 on Christmas-related purchases in 2015. This is a 15 percent increase from 2014. While this number ebbs and flows each year, it’s safe to say that buying gifts is a priority for many each December. 

But it’s unlikely that spending more money and buying more presents will make you — or your family — smile any bigger. Studies show that participating in family and spiritual activities during the season actually may help you feel more satisfied than spending more money. 

So rather than spending another Saturday afternoon at the mall, find a family activity instead. Take an ice skating lesson, go see a movie, or spend time baking in the kitchen. Even if it’s just one less shopping trip, it’s a step in the right direction to finding true holiday happiness.