BANGOR – The rambling house on the quiet side street is typical of Bangor’s handsome old wood-frame homes. But inside the house Thursday, the high-ceilinged rooms were filled with visitors and well-wishers, gathered to honor the 30th anniversary of Project Atrium, a residential treatment program for teens with substance abuse and mental health problems.

Eric H., 18, led a tour, showing off the family-style kitchen, the comfortable living room and a maze of sunny upstairs bedrooms, all supernaturally tidy for a “family” of seven troubled teenage boys.

“They make us keep it pretty clean,” Eric said.

A similar Project Atrium facility for girls is located in a different Bangor neighborhood – the locations are protected for the privacy of the young clients. The two facilities share a combined annual budget of about $1 million, most of it funded by MaineCare, Maine’s Medicaid program.

Eric – who developed a dependency on prescription painkillers and dropped out of school in ninth grade – said he first came to Atrium House as a condition of his release from a juvenile detention facility. He bolted after a couple of months, chafing under the restrictive environment. “I wasn’t ready to change,” he said Thursday.

But another incarceration for violating parole convinced him. Shortly after his release he came back to Atrium House on his own, under a special agreement with the state for young adults with plans to attend college.

“I realized this place could really help me,” Eric said. “This is a great place.” With support from Project Atrium, Eric earned a high school general equivalency diploma and has applied to the automotive technology program at Eastern Maine Community College. He has been clean for months now, he said, and expects to stay that way. He’s looking for an apartment.

Youngsters come to Project Atrium from a variety of backgrounds, but the majority is either court-ordered, wards of the state or both. Earning points for good behavior, they progress from a very restricted, “eyes-on” status to a maintenance level that allows them unsupervised time in the community, time alone in their rooms, a daily walk and a later bedtime.

Along the way, they participate in group and individual counseling, a 12-step program, household chores and schooling, either through the public school system or an alternative such as Job Corps or the Training and Development Center.

According to treatment specialist Amy Trueworthy, the average length youth stay in the program is six months to a year. “After that, typically, it gets harder for them to be here,” she said. “They’ve done the work and they’re ready for a less restrictive environment.”

From Atrium House some teens move back home with their families, while others may be placed in group homes or, like Eric, they may transition to their own apartment.

Project Atrium’s executive director John Jacksa said the measure of each client’s success is different. Short term, he said, staff members look for a demonstrated ability to “function in the community” – keep up with school responsibilities, work through personal conflicts, hold a volunteer job.

Longer term, “it’s largely subjective,” Jacksa said. Some former clients stay in touch and report back voluntarily, while others drop out of sight. “This tends to be a very transient population,” Jacksa said.

Thursday’s guest of honor was Maine author Martha Dudman, who has written about her daughter’s experience with substance abuse in her book “Augusta Gone” and about her own early years in a second volume, “Expecting to Fly: A Sixties Reckoning.”

Dudman spoke and read passages from her books to an attentive audience.

“When your kid’s in trouble, it strips your life down to the bone,” she said at the end of her talk, “and you’re never the same afterward.”