updated 04/14/2011 AT 10:55 AM ET
•originally published 04/14/2011 AT 8:30 AM ET
Walking the red carpet at New York City’s Museum of Modern Art this week, Michael Douglas was feeling grateful for all the well wishes he’d received from friends and fans as he battled cancer.
“I feel great!” the actor, 66, told PEOPLE at Tuesday night’s event to celebrate Carnegie Hall s 120th anniversary. “I feel a tremendous amount of support from so many people.”
Absent from the event was his biggest supporter: wife Catherine Zeta-Jones. Hours later, it was revealed that she has quietly sought healing of her own. Her rep says the actress recently checked into a facility for a few days to treat her bipolar II disorder.
The revelation was surpsing to many, not least because the Oscar-winning actress and mom-of-two stayed steadfastly positive in public while sticking by Douglas’s side through a grueling six-month battle with cancer.
But behind the scenes, those close to the actress say she felt the strain. Her rep acknowledged the timing of Zeta-Jones, 41, seeking treatment was in part connected to “the stress of the past year.”
Adds a friend, “Catherine has had to deal with Michael’s illness, and that’s been hard.”