Mentally unstable? Unless I missed something about Sinead Oconnor, that sounds kind of harsh. What does mentally unstable even mean? You shouldn't label people.
Explanations for behavior don't require a lot, but they need to be specific or you are just talking trash. That's why if I said maybe Sinead or people of similar type have Tourette's syndrome it's not a label. It's a very specific set of behaviors that can be studied in clinical trials. It's not rocket science some people are just prone to blurting things out.
Some people are just socially awkward and nobody tries to help them. But I do. I'm probably the worst person for the job, but I do try and sometimes succeed. I don't see a point in trying to make it harder for people. Plus I think, how bad can any celebrity or media person really be? They live for hype!
Don't get me wrong I love all kinds of music. But these are the same people who gave us "Turn down for what". I mean seriously. Nobody is asking if you would marry Sinead Oconnor's ego.