An eyewitness said: "Catherine was on his [Michael's] arm much of the time. She seemed really relaxed and happy. I saw her with a cocktail and she was socialising and enjoying the evening ... Nothing seemed out of the ordinary, and they both seemed to be having a good time."
The 43-year-old Chicago star, who has two children, Carys, 10, and Dylan, 12, with Michael, first sought medical help in 2011 when she spent time in a Connecticut-based mental health facility and her spokesperson Cece Yorke confirmed she re-entered treatment in recent days.
She previously said: "Catherine has proactively checked into a health care facility.
"Previously Catherine has said that she is committed to periodic care in order to manage her health in an optimum manner."
A friend of the star's added that she simply wants doctors to monitor her medication this time, saying: "There was no big problem. This was just a good time to do it. She is in between projects.
"This has always been part of the plan. She would manage her health. She is vigilant about it."
- Bang! Showbiz