Michael Douglas in New York on April 13
Michael Douglas braved the rainy New York City weather for a solo stroll Wednesday, the same day that it was disclosed his wife, Catherine Zeta-Jones
, had entered a facility to receive treatment
for her Bipolar II disorder
Zeta-Jones, 41, who stuck by her husband's side during his recent cancer battle
, spent about five days in treatment, according to a friend.
"There's no question it's been a stressful year," the friend told PEOPLE at the time. "Catherine has had deal with Michael's illness and that's been hard."
But Douglas, 66, wasn't solo for long.
The next day, the actor reunited with his wife over lunch at a Pizza Post in Connecticut, near the couple's home.