(NewsNation) — The smartphone has become an everyday feature of American high schools as kids use them to browse the internet and follow their friends’ activities on social media networks.

But adolescent smartphone usage has come under increasing scrutiny in recent years, as some mental health advocates worry that excessive screen time and social media usage can promote increased levels of anxiety, depression or loneliness.

That was one of the concerns that motivated Scarsdale High in Scarsdale, New York, to implement a new campaign called “Off and Away for the Day.”

The 1,500-student high school began the school year encouraging students to abide by a three-level system for cell phone usage.

Level 1 covers most of the school day, when students are required to turn their phones off while they are in class. Teachers can enforce this rule within their classroom as they wish.

During Level 2, which occurs in homeroom or common periods like lunch, students can briefly check their phones but aren’t allowed to use them for prolonged periods of time on things like social media or games.

At Level 3, students can use their phones to listen to music or a podcast during their free period, but they’re encouraged not to use them for social media or gaming, just like in the previous levels.

The initiative was the brainchild of Jennifer Rosenzweig, an English teacher who had long worried about the impact of excess cell phone use.

“Six years ago our department chair brought us together because of what we were noticing specifically in English in terms of students’ ability to read, students’ ability to focus, to concentrate, to read deeply, to tackle difficult texts, to handle sophisticated language, ideas,” she said. “We really started seeing in the last 10 years a huge drop off in that ability.”

The faculty spent years studying the problem and researching the impact of excess cell phone use. This fall, they decided to implement the new campaign, with guidelines that are voluntary but encouraged schoolwide.

On the first day of school, they showed students a video featuring testimonials of dozens of teachers at the school emphasizing they’re implementing the campaign out of care for the students, and followed up during their first school assembly as well as in workshops for parents.

Now, months after the launch of the campaign, school officials say they’ve seen a change at Scarsdale. The kids are grateful for the initiative and are enjoying school more.

“I think kids are making eye contact and smiling at each other in the hallways instead of being glued to their screens,” said school principal Kenneth Bonamo. “And in classes, you’re seeing much less student use of the phone, you’re seeing kids thinking, concentrating, focusing, engaging without that distraction.”

Rosenzweig added that teachers are also seeing improvements.

“Pretty much all the teachers that I’ve spoken to…say it’s much better in our classes,” she said. “We can say off and away and the kids put their phones away in the class, there’s no argument within the class.”

But Scarsdale school officials did note that they continue to see widespread cell phone use in the hallways, where they aren’t penalizing students for not abiding by the guidelines.

“This is not a school that has ever been built on policing anything. We do everything…in a more thoughtful way, more bottom-up,” Rosenzweig said.

Scarsdale’s teachers and administrators see their mission as gradually changing students’ mindsets about excess cell phone usage.

Rosenzweig herself is an alumnus of Scarsdale High, and noted that in the 1980’s, smoking among students and teachers alike was common. She sees the campaign to limit cell phone usage as tackling a similar social problem over the long term.

“We can’t just think this is going to be solved in a month, six months, a year. It’s not, right? This is about changing culture,” she said.