01/31/2008 at 05:00 PM EST
star Justin Chambers checked into UCLA Medical Center's psych ward earlier this week, but has checked out.
He "was exhausted and suffers from a sleeping disorder," his rep tells TMZ.com
. "He went in voluntarily to get some help."
Chambers plays Dr. Alex Karev on the ABC drama.
The UCLA Medical Center is the same facility where Britney Spears
is currently under a 72-hour psychiatric hold.