Catherine Zeta-Jones is being praised for her stunning revelation that she's undergoing treatment for bipolar disorder.
Bipolar disorder is characterized by dramatic mood swings. Zeta-Jones has biopolar II, which doctors say has longer low periods.
Psychiatrist Gail Saltz told INSIDE EDITION, "In bipolar II, you see alternating periods of very low mood with higher mood, but not so high that you lose touch with reality."
Michael Douglas has been spotted coming and going from the couple's home on the Upper West Side of Manhattan, but Zeta-Jones has not been seen since undergoing treatment.
Now people are taking a fresh look at some of her recent public appearances for signs that the star was alternating between wild moods, from manic elation to deep depression.
People noticed her emotion of elation at the Tony Awards last June seemed over the top. We now know her husband, Michael Douglas, had already been diagnosed with stage four throat cancer, but it hadn't been announced yet.
But her mood was radically different a few months later, at the beginning of Douglas's radiation treatment when she had a memorable meltdown with photographers at JFK Airport.
Through it all, Zeta-Jones managed to maintain her glamorous public face at events like the Golden Globes, and when she met Britain's Prince Charles, who asked how her husband was doing.
But the prolonged stress finally caught up to her earlier this month when she finally checked herself into the world-famous Silver Hill Hospital in Connecticut.
Saltz told INSIDE EDITION, "The treatment in general for bipolar disorder is first of all, medication. Mood stabilizers. Medication that keeps your mood even."
After Douglas announced he was cancer-free in January, INSIDE EDITION caught up with the couple at the Palm Springs Film Festival, where Zeta-Jones talked about the toll the past year has taken on her.
"It's a hard road and you just have to find the strength, which somehow, you do," said Zeta-Jones.