Book where teen wakes up to find he's alone in a major city; turns out he's part of a strange psychological experiment on another planet

Question

I must have read this book about 15 years ago or so. It was intended for young adults.

The thrust of the story is this kid wakes up to find that his parents are missing. Upon further exploration, he realizes he's the only person still left in this major metropolitan city. He comes across another girl his age however, I think her name was Skye.

They explore and come to find out that they're actually part of some psychological experiment and are in a synthetic environment on another planet. In essence, scientists wanted to see if someone taken from reality and placed in another environment could survive solely on imagination. The "city" they are in is merely a projection from their minds.

As the main characters realize they're not really on Earth, reality sets in and the poisonous, hostile environment becomes their reality. The scientists, dressed in spacesuits, implore them to come to safety. Instead, the main characters feeling betrayed, attempt to "believe" they are really on Earth and things go back to normal.

Answer 1

The Vanished (The Outer Limits #7) by John Peel

Where is everybody?

The alarm clock goes off. You wake up and get ready for school, just like every other day. So what's the big deal? Well, what if one morning you suddenly discovered that you were one of the last surviving people on Earth? That's right, everyone else has disappeared. No idea how, no idea why, just...gone--vanished. This has come true for a small group of teenagers who have just awakened to their worst nightmare.

But it gets worse. Someone--or something--is hunting them down.

Per amazon reviews

Nick and Skye, two strangers, both wake up to find that, oh no!, everyone is missing! They have to find what caused the disappearance of everyone before they too become The Vanished.