Reports surfaced at the end of last year that McDermott cheated with a woman while he was shooting a show in Toronto.
Now Dean said in a statement, "I am truly sorry for the mistakes I have made and for the pain I've caused my family. I take full responsibility for my actions and have voluntarily checked myself into a treatment center to address some health and personal issues. I am grateful to be getting the help I need so I can become the husband and father my family deserves."
Sources told People.com that McDermott, 47, is receiving intense treatment but is allowed to leave to visit his and Spelling's four children -- Liam, 6, Stella, 5, Hattie, 2, and Finn, 15 months -- at their house. "Their priority right now is their children," a source added.
Although Spelling has been putting on a brave face, posting happy family pictures on Instagram and her blog, an insider told People that Spelling was "much more heartbroken than anyone realized… she could stay with him or not. God only knows.”
Reality TV star Dean McDermott, best known for being married to TV heiress Tori Spelling, has checked into a treatment facility to deal with “health and personal issues.”