The O.C. fans are seriously worried about Marissa Cooper this morning.

TMZ broke the news that Mischa Barton was hospitalized yesterday morning after she was acting unusually in her backyard. It’s being reported that her neighbors were the ones to call police and paramedics after they caught the actress in only a dress shirt and tie. She was allegedly leaning over her fence talking about her mother being a witch, the world shattering and Ziggy Stardust.

This is really upsetting. Mischa was voluntarily taken to the hospital for mental evaluation. There’s no telling when fans will get answers about what’s really going on inside Mischa’s head, but it’s clear that she needs some professional help. It’s great to hear that she was cooperating and following orders as she may realize she needs this help as well.

WATCH: THE CAST OF ‘THE O.C.’ TRANSFORM BEFORE YOUR EYES

It’s important to note that Mischa is no stranger to this kind of behavior. Back in 2009 she was placed on involuntary psychiatric hold. Her rep commented on this stint in the hospital years ago and said, “Mischa has been hospitalized per the recommendation of her doctor and is resting in the hospital. We assisted her with a medical issue and removed her from her home.”

The O.C. alum commented on her 2009 hospitalization in 2013. She said, “It was a full-on breakdown. It was terrifying, straight out of Girl, Interrupted. Story of my life. I was never suicidal. I was just overworked and depressed. But one slip of the tongue in a heightened moment and you find yourself in that situation.”

She said this whole experience was an eye-opener. Mischa continued, “I accepted this was time I needed to be away from work, my family and all the pressure. I had been through the wringer.”

This is heartbreaking that she might be back in the same situation. However, she is in good hands. It’s amazing that her neighbors were aware, alert and made the right decision to call police when they thought Mischa could be in danger.

Here’s to hoping she is relaxing, resting and makes a full recovery soon!

Click through the gallery to see the stars you had no idea were on the show!