That's almost never the case. And how can some stranger at a call center know this? Mentally ill people are unreliable narrators of their own circumstances. They're prone to exaggerations, delusion, rants, lies, subterfuge, concealment, verbal abuse.
If someone called 998, then yes, please listen to them. Listen attentively, validate their feelings, but soothe and comfort and reassure them. There are systematic ways to do this and they can get results.
But never ever call 998. Beware if someone offers to do so. Your hospital incarceration will be more traumatic, damaging, and expensive than any other alternative.
Get help before it gets to that point. Seek out good therapists and support groups when you're sane and calm, and stick to your treatment. Do it in-person, face-to-face. There is no substitute.