The 5150 involuntary psychiatric hold on Amanda Bynes, 27, was apparently the last straw for Nick Cannon, 32.
The "America's Got Talent" host wrote a heartfelt letter Wednesday on his website to address the fact that he sees Bynes' situation as "no laughing matter."
Bynes is currently being detained for a mental health evaluation after an incident two weeks ago that involved a fire outside a residential home in Thousand Oaks, Calif.
"I tweeted a few weeks [ago] about how the entertainment industry just consumes people and spits them out like flavorless bubblegum," Cannon said.
Cannon added that some teenage stars become the breadwinners of their households before they can even drive, and that they were never told "NO."
"I call this 'access to excess,'" he said. "Whether it's fame, money, sex, drugs, attention. It's all a dangerous addiction."
The former "Drumline" star also said that while lacking a support system and believing her family had turned its back on her, he understood why Bynes might feel "alone in that dark hole."
"You become paranoid, frantic, manic, and irrational because you can't bounce your thoughts or ideas off … anyone anymore," he said, referring in part to Bynes' Twitter rants and attacks on other celebs.
"The ultimate magnifier" is what Cannon called the media, causing frail celebrities to burst into flames.
"So I say to my sister Amanda Bynes, you're not alone," he said. "I'm here for you. I understand. … I'm here! Call me!"
A decision will be made in the coming weeks on whether Bynes' parents, Lynn and Rick Bynes, will be granted legal custody over her.