Justin Chambers by Albert L. Ortega/ WireImage.com Justin Chambers by Albert L. Ortega/ WireImage.com
Justin Chambers'

recent stay at the UCLA Medical Center psych ward was due to a sleep disorder that he's had for a long time, he tells

People. In his first interview since the stint - which came on the heels of Britney Spears' stay at the same venue - Chambers says, "It's an issue that I've had for a while." He explains, "It's a biological sleep disorder. Your mind keeps racing, and your body is tired. It wants to go to sleep, but it can't." The dad of five has also been in the news lately, not just for his role as Dr. Alex Karev on the soon-to-return Grey's Anatomy, but for his reported disclosure that he had a vasectomy after child No. 5. It's nice to see that he's slowing down and hopefully getting some sleep. - Anna Dimond Related: " "Exhausted" Grey's Star Checked into Britney's Ward " Justin Chambers Is "Doing Great" After Hospitalization