Country music star Keith Urban credits his stint in rehab for helping him bond with new wife Nicole Kidman. The 39-year-old checked into a rehab facility in October (06), just four months after marrying Kidman in their native Australia. He tells US morning show TODAY, "They say grief makes hearts and closer bonds than joy ever can. We've been through a lot, and she's been extraordinary." Urban says words can't describe the lessons the couple have learned saying, "I can't really quantify it, because it's not a sound bite what we've learned. But, it's really profound." The singer, who has admitted to a past addiction to cocaine and previously underwent rehab in 1998, says his life had become "unmanageable" and he sought treatment to get back on track. He adds, "This disease of addiction, you know, it's nothing to do with contentedness and happiness, because I had all of that. "But I wasn't doing what I should be doing to maintain the road I was on previously, so it was a big wake-up call to get back on the road."