May is Mental Health Awareness Month. And advocacy groups say that in a given year, nearly one in five adults experience mental illness.
One Northern California teacher, Erin Castillo, is encouraging students to reveal their own struggles through a simple exercise. She created a poster that serves as a way for students to share their feelings -- a visual representation of how her class is doing emotionally.
Here's how it works: Kids write their name or initials on the back of a post-it note and stick it to the poster, in the section that describes how they're feeling. Castillo then pulls aside any student who puts their name in one of the bottom categories -- "having a hard time" or "in a really dark place."
"Something that's really huge is the stigma around mental health… of just people not feeling comfortable sharing where they really are," Castillo told Jamie Yuccas for "CBS This Morning. "And a lot of my students were like, 'Well, that's just how the world is,' and that's heartbreaking to hear."
Castillo said she was inspired to create the poster by a tragic event she experienced when she was younger.
"Actually I went here my freshman year and I witnessed a stabbing," Castillo said. "My mom could vouch that I would cry a lot after school and I just felt like I was kind of invisible to a lot of my teachers, and part of that was I never talked about it ... because I didn't feel comfortable talking about it, because no one encouraged me to talk about it."
Now kids in her class say the check-ins and activities like sharing circles have helped them open up about everything from battling depression to trouble at home.
"Once I, you know, came out from that dark place, and I started to open up more and more and more," Daniel Ferguson Morales said. "I feel, you know, my life has been so much better."
"Any kids out there. I'm encouraging you to be like me. I'm encouraging you to talk to your teachers," he said.
Castillo said the activities have not only made her class more empathetic and kind. They've also made them better students.
"Their grades have gone way up this year, their self-esteem has gone up," Castillo said. "They're believing in themselves."
In analyzing similar "social and emotional learning" programs involving more than 270,000 kids, researchers found their grades improved by 11 percent.
Now, Castillo's message is going viral. After posting the board for her more than 27,000 Instagram followers, dozens of teachers, some as far away as New Zealand, have created their own versions.
Castillo hopes the little notes will continue to make a big difference.
"I think giving up that little bit of time to make sure that we are there to say to our students, 'I am here for you, I care about you. How can I help you today?' I think this could be a way to change the world to go in a new direction, and hopefully we get to a place one day where everyone can talk about where they're at," Castillo said.