I would absolutely echo that. I don't think you want to tell people that this will be “the worst”, because then they'll say they're out and they won't do it, and you need people to do it. I think you can just speak in generalities to people.
You can tell them that there will be stresses, and you can give them some ways to deal with these stresses throughout the trial. As Ms. Swan said, you can give them some good mental health tips, i.e., “Over the next few weeks, you're going to be experiencing some of these stresses. Here are good ways to deal with them.” It's never a bad idea to do that.