Drug use, depression, unwanted pregnancies, sexually transmitted diseases, suicide — these and more begin to seep into a child's life around adolescence. And yet that's when doctors and nurses are seeing young people far less frequently.

Parents no longer are bringing their kids in for child wellness visits or the slightest flu, immunization requirements have been fulfilled and teens themselves are beginning to feel invincible.

That's the health-care gap the Petaluma Health Center is trying to bridge with the opening of its first high school-based health center. The clinic, which opened earlier this month at San Antonio High School, is one of two school-based clinics the health center plans to open over the next year. The second will be at Casa Grande High School.

In other parts of the country, school clinics are part of a growing trend to bring such things as primary health care, confidential family planning services and mental health services directly to students. Until now, the only high school-based health center has been the Elsie Allen Health Center in west Santa Rosa.

"Not only do teens need access to good medical care, if we want to lower rates of teen pregnancy and abortion and assure that teens can graduate, we need to make sure they have access to good, high quality reproductive health services," said Lynn Silver-Chalfin, Sonoma County's public health officer.

The new clinic is in a modular building in the parking lot of San Antonio High School. It is equipped with two general medical exam rooms and a mental health counseling room.

Funding to build the clinics primarily came from a federal grant of $400,000, said Jeanne Zabout, Petaluma Health Center's chief operating officer. Last month, the Sonoma County Board of Supervisors approved $150,000 for Petaluma's two school clinics.

Darcie Larimore-Arenas, a physicians' assistant at the clinic, said it initially will cater to San Antonio students and those at neighboring Valley Oaks Independent Study School. After the Casa Grande clinic opens, services at the clinics eventually will be opened up to the general public.

The clinics are equipped to provide a range of medical treatments and procedures, including physicals, sports physicals, Pap tests, IUD insertions and other contraceptive methods, suturing, biopsies, urine dips and well-child visits.

Under state law, such clinics can provide confidential reproductive health services to teens. The treatment of other medical conditions, such as urinary tract infections, bronchitis, ear infections and ankle sprains require parental consent, and the clinic has been collecting signed consent forms from parents since the beginning of the school year.

"You want it to be a friendly place that's easy for them to access," said Jennifer Brazinsky, a licensed clinical social worker who provides mental health counseling.

"A lot of kids struggle to access health care if they are in family situations that are difficult," she said.

When some young people hit adolescence, they sometimes begin to want more "independence in their health care decisions," Brazinsky said. "There are certain things that kids need to explore on their own first and then figure out how to broach that subject with their parents. Being able to go somewhere and know that you will be treated confidentially is a godsend."

Brazinsky said the most common mental health issues for teenagers are depression, anxiety, suicidal thoughts and peer relationship problems.

"So much of that stuff feels overwhelming to an adolescent," she said.

There are 226 school-based clinics in California, according to the California School Health Centers Association. Of these, 45 percent are on high school campuses, 30 percent are in elementary schools and 10 percent are in middle schools.

Many of the association's school clinics are on campuses that serve low-income students.

The number of school clinics in each county varies widely. Alameda County, with a population of 1.6 million, has 22 school clinics. In contrast, Sacramento County, with 1.5 million people, has one clinic.

In the North Coast, Napa, Lake and Mendocino counties have no school-based clinics, according to the school clinics association.

Serena Clayton, executive director of the association, said that federally qualified health centers often are the principal players in setting up school clinics. Counties with a strong network of health clinics usually have more school-based clinics.

Sacramento has few federally qualified health centers compared to Alameda, she said. But, she said, "once there are a few it starts to spread because people see the benefits."

(You can reach Staff Writer Martin Espinoza at 521-5213 or martin.espinoza@pressdemocrat.com)