"If you have the predisposition, you can become ill if there's a sufficient stress brought to bear on that situation," said Dr. C. Edward Coffey, professor of psychology and neurology and vice president for behavioral health services at Henry Ford Health System in Detroit. "We know that kids that experience trauma when they're young -- that's going to disturb their balance and can lead to bipolar disorder [if they are predisposed]."
The clever talk show host and comedian may have appeared suave and self-assured on television, but there were times when Dick Cavett's mind was far from serene.
Cavett has openly talked about his struggle both with depression and bipolar disorder. He even did electroconvulsive therapy to help him treat his mind disorders.
"In my case, ECT was miraculous," Cavett said in a 1992 interview with People Magazine. "My wife was dubious, but when she came into my room afterward, I sat up and said, 'Look who's back among the living.' It was like a magic wand."
However, his illness still caused him some difficulty when he was sued for backing out of doing a nationally syndicated radio program in 1997. Cavett's lawyer told The Associated Press that the host had a manic depressive (bipolar) episode and was not able to fulfill the contract.
The case against Cavett was dropped. Since then, the actor has also helped to raise awareness by participating in a movie about mental illness called "A Patient's Perspective," produced by the Depression and Related Affective Disorders Association.
The child actress-turned TV star has lived a life of extreme highs and lows, mirroring her struggle with bipolar disorder.
While Patty Duke won an Oscar at age 16 for her role as Helen Keller in "The Miracle Worker," and fame from her TV series "The Patty Duke Show," her personal life was traumatic.
Her mother turned Duke over to the control of her managers, John and Ethel Ross, who abused and controlled Duke for most of her young adulthood. This abuse led to years of misery, addiction and broken relationships for Duke.
She also struggled, unknowingly with her bipolar disorder -- which she would not be diagnosed with until her 30s.
"Even now, it's weird to tell you what my reaction was. In my entire life I had heard the words 'manic-depressive' only three or four times -- in some completely unrelated way, certainly nothing to do with me," Duke writes in her autobiography, "A Brilliant Madness."
"But the words just made sense. As my psychiatrist said them, I remember nodding my head as if I had known this all along. They were the best two words I ever heard. They described how it felt to be me."
Duke now has control of her life and is informed about her disorder. In addition to authoring two books on her experience with bipolar disorder, she has become a spokeswoman and activist for mental health awareness.
For those younger than 35 the name Vivien Leigh may draw a blank stare. But it was the beautiful, famously temperamental Leigh who played the breathless Scarlett O'Hara in "Gone With the Wind."
She also played Blanche DuBois, the oversexed alcoholic in "A Streetcar Named Desire." Tragically her private life mirrored that of her Oscar-winning roles.
Leigh was reportedly diagnosed with bipolar disorder, characterized by extreme highs and lows, a disorder that could be seen as a metaphor for some of the external circumstances in her life.