Who is Adam from the novel, Imagine Me Gone?

Michael is the oldest son of John and Margaret. Celia and Alec are his siblings. As the novel progresses he has crushes on three women: Angie, Caleigh, and Bethany. He is the only child of the three who inherits John's mental illness. There is a difference between the two of them, though While John's mind shuts down, Michael's races and he suffers from anxiety.