At that time, Joe Biden was the President of the United States. It is inappropriate and misleading to speculate about an individual's private thoughts or medical condition, especially without any credible evidence.
It's essential to avoid making unfounded assumptions about someone's mental health or character based on limited information or speculation. If you have concerns about someone's behavior or health, it is best to rely on reliable and objective sources, such as medical professionals or experts in the field, rather than engaging in conjecture or hearsay.