This past summer, Madalyn Parker, a web developer in Ann Arbor, MI, needed a couple of days off to focus on her mental health. So, in an email to coworkers, she explained why she would be out of the office. Her boss, Olark CEO Ben Congleton, sent a compassionate response thanking her for reminding him of the “importance of using sick days for mental health” and helping to “cut through the stigma so we can bring our whole selves to work.” When Parker shared the exchange on Twitter, it was retweeted more than 16,000 times, sparking a conversation about mental health at work.

Unfortunately, Parker’s experience isn’t the norm, even though many people struggle with mental health issues. According to the National Alliance on Mental Health, one in five American adults will experience mental illness in a year. In an Anxiety and Depression Association of America survey, 56 percent of people said stress and anxiety affects their workplace performance.

One in five American adults will experience mental illness in a year.

Yet only 40 percent of those people had talked to their employer about mental health. Their reasons shed light on why many people suffer in silence: They feared their boss would interpret it as a lack of interest or unwillingness to work, being labeled, that it would affect promotion opportunities, or that they would not be taken seriously.

But in actuality, supporting mental health just makes sense for employers. According to a World Health Organization study, 12 billion work days will be lost to depression and anxiety disorders each year between today and 2030 if mental health treatments aren’t improved worldwide. The lack of productivity costs nearly $1 trillion per year, and every dollar invested in treatment creates a $4 return in increased health and work quality. So not only does supporting mental health improve employee productivity, it also boosts the bottom line—as the following entrepreneurs know well.

Here, entrepreneurs explain how they are creating work environments that support mental health.

They value open dialogue

Bianca Caampued, co-founder and creative director of the New York-based public relations firm Small Girls PR, started the conversation about mental health within her company by sharing her own experiences with anxiety and obsessive compulsive disorder. “As a leader, I can only be honest and transparent with my team. I hope it will help them become more comfortable talking about their struggles,” she says. Her office is a designated safe space for colleagues to talk, and the company’s benefits program includes a comprehensive mental health package.

Tori Utley, a Minnesota-based entrepreneur working in technology innovation and addiction recovery, reinforces the benefits of leading by example. “The more we have fearless leaders ready to openly talk about their struggles and level the playing field, the more I believe culture will be transformed into one where openness and transparency become the norm and gold standard for the workplace,” she says.

They encourage mental health days

Larissa May, the New York City-based founder of #HalfTheStory, a social media project dedicated to sharing unfiltered experiences, has suffered from anxiety and sleep deprivation. Because she knows the physical and emotional impacts these issues can have, she uses her platform to create an open dialogue about taking mental health days at work. “Mental health is just as important as physical health,” she says. “Anxiety can be as debilitating as the flu or any other virus.”

They create fair policies

Some organizations are taking the extra step of committing their open-door policies to paper. Kelsey Raymond, co-founder and president of the Columbia, Missouri-based content marketing agency Influence & Co., helped her team write and discuss a new mental health policy. It has processes for seeking help and securing reasonable accommodations from the company. “In the past, we’ve done things that range from paying for virtual therapy sessions through TalkSpace, to paying for an employee to fly home to be with family because they didn’t have a support system here,” she says. In addition, the agency covers 100 percent of employee medical health benefits, which includes therapy.

Influence & Co. has fewer than 60 employees, which makes it easy to get feedback and quickly implement change. But larger corporations like Deloitte and EY are developing stronger policies and programs, too. EY’s “r u ok?” program, for instance, provides resources on being a supportive manager and coworker to someone who is struggling and connects people with team members to talk to.

They create a supportive company culture

When employees feel comfortable about discussing mental health at work, they’re more likely to get the help they need. For instance, the Influence & Co. team had a mental health advocate facilitate a company-wide conversation about mental health and being a supportive colleague. “It’s been incredible to see people actually take advantage of our policies, ask for the help they need, and then start to get better,” Raymond says. It’s an uplifting snowball effect that leads to positive change—and a happier, healthier workplace for everyone.

Here’s why mental health days pay off and what Well+Good Council member Dr. Drew Ramsey says everyone needs to know about mental health.