Two years before Caitlyn Jenner showed up on this week’s cover of Vanity Fair, Oliver Bishop was in crisis.

The Sonora teen’s grades had dropped, and he’d become suicidal as he sensed that puberty was beginning to trap him in a female body that seemed alien to the boy he had always been inside.

“You know you’re a guy,” he said, “but everybody doesn’t see it that way.”

Now, as the nation sees a growing acceptance of transgender people such as the former Olympian Jenner, Bay Area therapists and physicians are seeing a surge in the number of families seeking advice — and sometimes medical intervention — to help kids whose perceived genders and bodies don’t seem to match.

“We have lifted the lid culturally,” said developmental psychologist Diane Ehrensaft, whose Oakland practice has seen a fourfold increase in the number of gender-questioning kids in recent years. “These kids have always existed, but they kept it underground.”

Her colleague, Steve Rosenthal, started the UCSF Child and Adolescent Gender Center three years ago and now serves 200 families, including Bishop’s, and has opened a satellite branch in San Mateo. The gender center took on 13 new families in May, the clinic’s busiest month yet.

A couple of months before Bishop’s 15th birthday, after years of trying to fit in as a girl in middle school, he ran across the word “transgender” on the Internet — and all his struggles suddenly clicked into place. “It was awesome,” seeing that others had blazed a path before him and “realizing there was something I could do,” said Bishop, who later persuaded his family to take him to the UCSF clinic.

One of the challenges now faced by gender specialists is sorting out the tomboys and boys enchanted by princess dresses from the truly transgendered.

“Sometimes we have to slow the kids down to give them space to think, because kids want to go fast and make things happen,” Ehrensaft said. But when kids express true urgency, she said, “sometimes we have to speed ourselves up.”

Some come to accept their bodies but continue exploring what it means to be male or female in their own way, Ehrensaft said. Others may discover that they’re gay or lesbian.

But for about 10 to 15 percent of these children it’s different, said Rosenthal, a pediatric endocrinologist.

Feeling they’re in the wrong body makes them miserable, he said. It keeps them up at night and gets worse as they hit puberty. And, he said, nearly all who feel that way into adolescence go on to be transgender adults.

For children who are “persistent, consistent and insistent” that their biological gender doesn’t match who they really are, it’s critical to act, Ehrensaft said. “Holding a kid back when they know there’s an intervention that could help them feels to them like they’re swimming in deep water, nearly drowning, and you’re standing with a life jacket around your arm and not giving it to them,” she said.

In a 2010 study by the National Center for Transgender Equality, 41 percent of transgender adults reported having attempted suicide — a rate 25 times higher than the general population. A quarter of transgender adults reported suffering from drug or alcohol addiction.

But the increasing presence of transgender people online and in the media have helped give young people the confidence to express the gender they feel themselves to be, Ehrensaft said. Parents, too, she said, are becoming more aware than ever of the suffering transgender teens face and the need to take children who resist traditional gender roles seriously.

“When a family says, ‘OK, let’s listen to this kid, let him wear dresses if he wants,’ they often say they find a kid they’ve never met before,” said Joel Baum, director of Oakland nonprofit Gender Spectrum. “A kid who’s suddenly happy.”

Bishop had known for years that he wanted to be male: At the age of 10 he started saving money with the idea of one day getting breast-reduction surgery. Five years later, when he finally learned about transitioning to a male, he resolved: “I’m either going to do it and be happy, or I’m not going to live life.”

At first Bishop’s parents couldn’t accept that the child they had always thought of as a daughter was determined to become their son.

“It took me a bit to become a really supportive dad,” said Bishop’s father, Dale.

For months they didn’t speak. But in the end, reading the suicide statistics for transgender teens brought him around.

“My kid’s not going to kill himself,” the older Bishop said. “I don’t care what he is, as long as he’s a productive person in society, and he needs all the support we can give him.”

UCSF and other gender clinics now often use reversible hormone blockers to delay puberty and the permanent biological changes that come with it until mid-adolescence. This gives children and families a chance to fully explore and be certain about their path before going on to sex-hormone treatments, which cause permanent physical changes.

For biological girls who know they are boys deep down, Rosenthal said, growing breasts and starting menstruation are “basically intolerable.” The same goes for transgender girls who feel physically trapped in a boy’s body, he said. Developing a deep voice and an Adam’s apple can feel like a permanent deformity.

Bishop started taking hormone blockers in spring 2013 at the UCSF gender clinic at the end of his freshman year. That summer he started taking testosterone to switch from female to male puberty. He has had surgeries to flatten his chest and remove his ovaries and uterus. He hopes his transition will be complete by this summer after one more surgery.

With the support of his family and community, Bishop is thriving, his father said. At 17, he’s a straight-A student, a popular drum major in his high school marching band and excited about heading off to college.

His only regret is not starting the transition sooner, before female puberty started to make changes that had to be rolled back with surgery.

So far, the easiest part of Bishop’s transition has been his coming out at school, he said. When he announced that he was now a boy to his freshman class, he recalled, “They were like, ‘Cool — and? That’s not a big deal.'”

This is typical of a generational shift in attitudes toward gender and sexuality, said Baum, of Gender Spectrum.

“It’s a movement being led by young people,” he said. “And the pace of it is remarkable. It has caught us staggering.”

Follow Nicholas Weiler at Twitter.com/Lore_Nick.