Do people with a diagnosis of schizophrenia or BPD leave a suicide note?

Schenidman was a guy who spent most of his life researching suicide.
Much of his work was focused around using the data from suicide notes.
This was a significant step forward in suicidology.

Not every person leaves a suicide note and that's an important chunk of
missing data that may be almost impossible to get hold of.

I wonder if a large number of the missing suicide notes would be for
people with a diagnosis of schizophrenia.