Michael Douglas loves Catherine Zeta Jones, but she has "her own issues".
The Hollywood couple's 13 year marriage has weathered Michael's throat cancer ordeal - which he was given the all-clear from in 2011 - and Catherine attending rehab for Bipolar II disorder twice, but friends say dealing with these things has taken its toll on their marriage, which they announced earlier this week they are taking a break from.
A source close to Michael told the Daily Mirror newspaper: "It's very stressful. He loves her but she has her own issues."
Catherine, 43, also found it difficult to deal with Michael's diagnosis and treatment for cancer, and wishes she could have done more to help him.
She has said in a previous interview: "I haven't had to deal with anything like that before. I wasn't as strong as I thought I could have been."