Taye Diggs Reveals Sister’s Schizophrenia Diagnosis, Says He’s 'Embarrassed' by His Previous Misconceptions (Exclusive)

“When she was diagnosed, she told me it was like the part of her brain that she enjoyed the most wasn’t her own anymore,” the actor tells PEOPLE

• Taye Diggs reveals his younger sister Christian was diagnosed with schizophrenia in her late 20s

• The actor says he initially had a lot of misconceptions about schizophrenia, only knowing about the mental illness through stereotypes portrayed on TV

• The siblings are now launching the “Live Your PosSCZible” campaign to raise awareness about schizophrenia and create possibilities for those living with the condition

Taye Diggs revealed that his younger sister Christian Diggs, 48, was diagnosed with schizophrenia.

Speaking exclusively to PEOPLE about launching the “Live Your PosSCZible” campaign, the 53-year-old actor opened up for the first time about his sister learning she had the mental illness in her late 20s and how that diagnosis impacted both of their lives.

Schizophrenia, which impacts 2.4 million adults in the United States, is a serious mental disorder in which people interpret reality abnormally, according to the Mayo Clinic. It is associated with hallucinations, delusions, and extremely disordered thinking and behavior that impairs daily functioning, and can be disabling.

“As you can imagine, we were all very surprised and scared and curious,” Diggs tells PEOPLE of Chirstian’s diagnosis. “I didn't know anything about it. Like most people, the only reference I had was what was portrayed on television and a whole bunch of stereotypes.”

“My sister's very, very smart, and she loves to use her brain. And when she was diagnosed, she told me it was like the part of her brain that she enjoyed the most wasn’t her own anymore,” he explains. “And that's what was very frustrating for her.”

Related: Schizophrenia Caused Eric Smith to Threaten His Mother's Life, but He Refused to Get Help — Here's Why

Related: Kyleigh Leddy Paints Vivid Portrait of Sister's Schizophrenia: 'She Became Another Person'

As her big brother, Diggs was eager to step in as a caretaker and help Christian in any way he could. But the star quickly realized that the most help he and his family could give was to stay on the sidelines of her mental health journey and simply support her as she found treatments that she says helped “piece my life back together.”

Diggs explains, “I was frustrated because it felt like I couldn't help her out in any way because I'm not a doctor. But once I put my ego aside and just kind of listened to the therapist, that was the role that meant the most to her. The most I could do, and the best I could do was be as supportive and patient as possible.”

He continues, “Now, when I speak to my sister, she lets me know how important that was, even though it seemed like I wasn't doing much. She let me know that it meant a lot and that put me at ease.”

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Although there is no cure for schizophrenia, lifelong treatment with medicines and psychosocial therapy can help manage symptoms. And once Christian was able to commit to therapy and receive proper medications, Diggs says she hasn’t been held back by her schizophrenia in the slightest.

“Once she started getting on the right medication and had a certain amount of therapy, then it started to click for her. It was night and day,” the All American star says. “We were just there to say, ‘Keep going. Don't lose hope. Everything's going to be fine.’ And then she came out of the clouds and we were all very thankful and grateful. And we felt lucky.”

“Christian helped me uncover the fact that there's hope. It's not like it's the end of the world,” he explains. “I could see her being able to make decisions and live out her ambitions and do all this stuff that I thought was not going to be within her grasp.”

Diggs admits that looking back, his previous “stereotypical” perspective about schizophrenia seems foolish now after seeing his sister’s experience firsthand.

“It's really easy to just make a judgment. It's so easy to just kind of put people in a certain box,” he says of the mental illness. “I feel silly because I thought it was so black and white. But now I know better.”

“I'm almost embarrassed to admit what I thought of her when we first heard this news, but she's such an inspiration,” the actor adds. “People just need support. They need a team around them that knows what they're doing, and they can literally achieve whatever they want. And I didn't realize this at the time.”

Related: Author Grace Cho Shares Her Mother's Story of Developing Schizophrenia at 45: 'I Was Terrified'

Now, the siblings are teaming up with Bristol Myers Squibb to launch the “Live Your PosSCZible” (LYP) campaign, telling their story and raising awareness about schizophrenia and the reality of what’s possible for those living it with the disorder.

Although they were nervous to go public with Christian’s diagnosis, Diggs admits that “it was a no- brainer," hoping it will help people change their mindset about the mental disorder — just like he did.

“When you're faced with a situation like this, it's important to realize it's not the end of the world, that you can do whatever you want to do. You just have to make certain adjustments. And so many people don't realize that,” the Rent star says. “I encourage people to not make judgements. To not fall into the trap of, ‘Oh, what's going to happen? She'll never be able to do this again.’ Try to avoid that and know that it's the exact opposite.”

Nowadays Christian is thriving, her brother says. Living independently, working as a carpenter in construction and being a part of this initiative as an advocate, she’s “making me proud,” Diggs adds.

“She's doing really great,” he says. “And she's so happy that she did this. It wasn't about her being embarrassed or not wanting people to know what she is challenged with. It was more about letting people know that you can do so much more than what people assume.”

“She’s really proud. And as a brother, that makes me feel good first,” Diggs tells PEOPLE. “But then it's also nice to know that we're hopefully changing people's opinions and perspectives, because that's what's important.”

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