Kristen Bell has spent the last two decades working in one of the world's most pressure-filled environments. Her biggest lesson for managing anxiety and depression: Don't let things fester.

"I don't wait for those things to find me," Bell tells CNBC Make It. "I have a preoperative list to combat them because I know they're coming."

Ever since college, the 41-year-old actor and star of "Veronica Mars" and "The Good Place" has struggled to manage her anxiety and depression, both at home and in the workplace. She first started taking medication to deal with her anxiety and depression while studying at New York University's Tisch School of the Arts, according to Self Magazine. Then, in 2016, Bell wrote an op-ed for Time titled, "I'm Over Staying Silent About Depression," in which she detailed her struggles with "dark clouds" hanging over her.

In the years since, she's become an advocate for mental health transparency across the country, encouraging people to get mental health check-ins and open up about their struggles.

For Bell, depression is not sadness or having a bad day. Rather, it's a "complete and utter sense of isolation and loneliness." The Covid-19 pandemic hasn't helped matters either, Bell notes: "Anxiety and depression [are] off the charts right now, especially for girls."

She isn't alone. Globally, more than 264 million people of all ages suffer from depression, affecting more women than men. Anxiety disorders affect more than 40 million adults in the U.S., and nearly one in five American adults have a mental illness of some kind, according to the National Institute of Mental Health.

Mental health disorders can affect a person's sleep, appetite, energy level and concentration — making it harder to be productive at work, and fully engaged at home.

Over the years, Bell has picked up a few simple tactics to manage her own mental health. Here are her top three strategies:

Talk about it

For years, Bell refused to open up about her mental health — fearing, she says, what other people would think of her.

When she finally decided to talk about her struggles, seeking help for her negative thoughts, she found that her mental health became easier to manage. The more she opened up, the easier it got — and the more other people opened up to her about their own struggles.

"Now, after seeking help, I can see that those thoughts, of course, couldn't have been more wrong," Bell wrote in Time. "It's important for me to be candid about this so people in a similar situation can realize that they are not worthless and that they do have something to offer."

For Bell, the key is to adopt a growth mindset — believing that you can change, develop and improve your mindset and abilities — whether you struggle with mental health yourself, or you know someone who does. "The more we all commit to a growth mindset, the more we all evolve," Bell says, noting that a stronger understanding of mental health can also help you better understand the people around you.

The language around mental health is also really important, Bell says: It's important to remember those feelings that you are having aren't "your feelings," but rather "a feeling that is passing through you."

"Sometimes, with a mental health issue, you just got to let them live," she says.

The mantra has even carried through to her parenting. When one of Bell's two daughters, Delta and Lincoln, starts crying, she asks them: "Do you want a solution to this problem you're crying about, or do you just want to let this feeling pass through you?"

Exercise

Bell says she works out a couple of days a week, specifically for her mental health — typically, a combination of cardio, circuit training and Pilates.

"I notice a big difference when I do and when I don't," she wrote in an Instagram post last year. "When I don't, I'm sad, irritable, anxious and lethargic. When I do, I'm content, motivated, peaceful and energetic."

Science backs her up: Research from Harvard Medical School shows that exercise can be an effective treatment in treating depression. "For some people, it works as well as antidepressants," Dr. Michael Craig Miller, assistant professor of psychiatry at Harvard Medical School, told Harvard Health Publishing in February. "Although exercise alone isn't enough for someone with severe depression."

Miller said low-intensity exercise sustained over time releases proteins called neurotrophic or growth factors into the brain, which cause nerve cells to grow and make new connections. The activity improves brain function, which in turn helps people feel better, his report said.

Call a timeout

Bell says when a stressful event starts to bubble up — whether that's at work or at home with her two daughters, and husband Dax Shepard — she immediately calls a timeout.

"I will go to my bedroom for 10 minutes, just to reset and regulate," Bell says.

During those timeouts, Bell says, she occasionally uses CBD products to help relax her. It helped her decide last year to co-found Happy Dance, a line of CBD skincare products, and it's a strategy she uses to help keep herself sane while helping run the startup. If feeling overwhelmed, she says, she jumps off work and Zoom calls 10 minutes early.

"You don't have to give a reason," Bell advises, especially if you're already open and honest with your coworkers about mental health. It's the "framework of putting on your gas mask first, and not being embarrassed about that."

In her own head, Bell notes, she often comes back to an Eleanor Roosevelt quote: "No one can make you feel inferior without your consent."

"I just don't consent anymore," Bell says. "I'm not embarrassed about any of the time I need to take to help myself, because that's making me a better me."

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