Not completely sure in that case if the trial had already started. My guess is the defense would request time off until he is well enough to be there.
When I did some psych rotations, I sat in with one of the psychiatrists that was determining whether a forensic patient was competent to stand trial. In this case, the patient told the doctor that he was going to go up to the judge in court and confess his crime. This is obviously not a good idea and not how it works in a court. So at that point, he wasn't competent and the doctor planned to meet with him further to try to educate and make sure he could help and not hurt his case.
