Exclusive: Sienna Ponce, Daughter of Carlos Ponce, on Her Struggle With Depression and Anxiety

When her daughter Sienna shaved her head, Veronica Rubio did not see it as a typical rebellious act of an 18-year-old, but as a desperate cry for help. "I was scared for her when I thought of what went through her mind, because she did it in the middle of the night, around 4 a.m., without telling anyone," says Rubio of her daughter with actor Carlos Pence. "You wake up to find that and it's very shocking. It reminded me a lot of Britney Spears a few years ago."

The Cuban American photographer, 47, also began noticing changes in Sienna's personality. "She became distant from us, she was more serious," she says about the high school student, who locked herself up in her room, lost interest in her favorite activities, started to sleep more during the day, and suffered insomnia at night. "I knew something was happening," adds Rubio, who was married to the Puerto Rican actor and singer, 48, for over two decades. She is also the mother of his sons Giancarlo, 21, and Sebastian, 19, and twins Sienna and Savannah, 18, whom they adopted in Russia when the girls were babies.

"I honestly didn't notice," Carlos admits about his daughter's mental health crisis, which the teen initially tried to hide from her family. "You have to be really vigilant. There are signs. Sienna is fortunate to have people who love her, but there are people who go through this and don't have anyone to even talk to. I know she will become an advocate, a person who will help other people seek help and heal." Sharing her story is her way of helping other people find the light. "My main reason is so that those who don't feel heard, loved, or understood will know that they are not alone in their feelings," Sienna tells People en Español. "Creating a safe community where we can talk about these issues openly is vital to help people recover from mental health issues and to prevent suicide."

Sienna's psychologist, Elizabeth Skjoldal, also spoke to People en Español about Sienna's diagnosis of anxiety and depression. "A lot of her feelings were kept inside, [she wasn't] able to talk about it. Usually behind the anger is sadness," the doctor says. "I felt sad, angry, anxious, and apathetic toward everything and everyone," Sienna recalls. "I couldn't control any of those feelings and they were taking over my mind."

Besides taking medication prescribed by a psychologist and going to therapy sessions with Skjoldal, Sienna felt better after activities like swimming, biking, playing with her puppy, and talking to her friends and siblings. "It's very hard to see the light at the end of the tunnel when you're still in the dark," she says, "but if I am doing it, I want to help other people do it, too."

If you or someone you know needs help or mental health services, call the National Suicide Prevention Lifeline at 1-800-273-8255, available 24/7. For more with Sienna and her family, look for the new issue of People en Español, now on newsstands.