FREDERICK, Md. — It’s a little after noon. Usually by this hour, David Weiss would be waking for the second time, still groggy from his antipsychotics. He’d have gotten up once at dawn, maybe made himself an egg with toast. He might have gone into the back bedroom to scan his ham radio or played a few chords on his guitar. Then he’d go back to sleep.

But on this day, he had somewhere to be. It’s easier to get up on days like this, days with a purpose.

And so at noon, he is sitting in an abnormal- psychology class at Shepherd University in ­Shepherdstown, W.Va., his arms crossed and a plate of pizza balanced on his lap. At 64, Weiss still has a full head of wavy silver hair and a broad, kind face and a bulbous nose that make him a dead ringer for a mall Santa. He wears a Hawaiian shirt that smells faintly of incense.

He’s giving a talk to the students about life with mental illness.