Catherine Zeta Jones hid her struggle with depression from Michael Douglas.

The 41-year-old beauty recently underwent treatment for Bipolar II disorder - which was triggered by her 66-year-old husband's battle with throat cancer - but the 'Wall Street: Money Never Sleeps' actor says his wife managed to conceal his condition from him for a long time before she sought help.

He said: "It's hard for your wife to say 'I'm depressed', you know.

"It's probably been going on for a while. But I wasn't really aware of it. You know Catherine and Brits in general - Catherine is Welsh, you never see them in a bad spirits right? They always give the stiff upper lip, carry on and this and that.

"I'm really proud of her. There are some great medications out there now for people, it's an issue that affects a lot of people."

While Catherine has now returned to work, Michael - who was given the all-clear from cancer in January following six months of chemotherapy and radiotherapy treatment - admitted their children Dylan, 10, and eight-year-old Carys do not know about their mother's condition because it came so soon after their father's illness.

He said on US TV talk show 'The View': "No, they don't know yet. We gotta give them a chance, they're just getting over the other issues.

"Of course the hardest part is not the kids at the school, it's the parents of the kids, you never know how much they're sharing with their children."

Michael has had a tumultuous year in which he has seen eldest son Cameron imprisoned on drugs charges and his ex-wife Diandra launch legal action in a bid to gain a percentage of his salary from recent movie 'Wall Street: Money Never Sleeps' and the actor believes his difficulties are "karma" for his previous good Fortune.

He said: "It's been a long year-and-a-half. Life had been good to me for a really, really long time and I was thinking I'm going to get hit by a truck, it's been too good.

"So this karma in the last year and a half has kind of balanced things out, so I feel pretty good for the future."

"I joke about it but in the last year-and-a-half my oldest son got incarcerated, sent to federal prison, my ex-wife sued me, I got cancer."