Michael Douglas, Catherine Zeta-Jones Separate
"They're taking a break," a source told the mag in the new issue on stands Friday. "The stress has taken a toll on their marriage."
Since marrying at the Plaza in 2000, the couple has faced numerous personal battles, including Douglas' cancer scare in 2010 and Zeta-Jones' recent diagnosis with Bipolar II disorder. Douglas' son, Cameron, is also serving a 10-year jail sentence for drugs.
Still, the couple hopes to suss out their problems for the sake of their family.
"They want the best for their kids, no matter what happens," a source said. (Zeta-Jones has two children with Douglas -- Dylan, 13, and Carys, 10.)