Before the most recent elections, people voted for an unwell person to lead the country. So it's not just someone can obtain the position, but that people actually chose to put one in office. Twice. Although, it was less well known on the first one.

"Saw a therapist once" =/= "unwell."

In fact avoiding therapy at all costs is a good sign of trouble.

The track record for preventing people in positions of trust from seeking out mental health care is terrible. It's just brushing problems under the rug and waiting for them to turn rancid. Don't interpret not seeking help as the nonexistence of a problem, especially if their career depends on it.

Does the Department of Defense still have a clearance disqual for ADHD?