Catherine Zeta-Jones' Bipolar Disorder: Were There Clues?

Catherine Zeta-Jones reportedly checked into Silver Hill Hospital in Connecticut on April 6 for what her rep says was a brief stay to treat Bipolar II Disorder. Were there clues that the Oscar winner has been battling manic depression?

The 41-year-old star had reportedly been suffering sleepless nights and chain-smoking and drinking to cope with the stress of husband Michael Douglas' battle with throat cancer. According to Gabrielle Carlson, M.D., professor of psychiatry and pediatrics at Stony Brook University Medical Center in New York, depression is a primary characteristic of Bipolar II, along with various states of agitation or irritability, punctuated by a mild form of mania in which the person can seem unusually upbeat.

Back in June when Catherine accepted her surprise Tony Award onstage for A Little Night Music at Radio City Music Hall, she delivered an excited but rambling speech until she was played off the stage by music. Was she manic, or just pumped with adrenalin?

Last October, the star broke down and froze at JFK airport after being surrounded by paparazzi. And in February, she flew into a rage in London when, after accepting a prestigious honor, she claimed that a photographer hit her during a crush to get a shot of her with her husband.

According to the Mayo Clinic, exact symptoms of Bipolar Disorder vary from person to person, and Bipolar II is less severe than Bipolar I; generally people can carry on with their normal daily routine. Instead of full-blown mania, they have "hypomania" -- a less severe form of mania -- and in Bipolar II, periods of depression typically last longer than periods of hypomania. Lithium is one of the drugs commonly prescribed to treat the disorder, as well as psychotherapy, such as cognitive-behavioral therapy.

The question on many people's minds now is will Catherine's Bipolar admission hurt her career?