Joan W. Denny, who had bipolar disorder for most of her life and was a longtime participant in Johns Hopkins University Mood Disorders Center-Symposium, died Jan. 11 of cancer at Gilchrist Hospice Care. She was 79.

Joan Weiskittel Denny was born in Baltimore and raised on Overhill Road in Roland Park. She was a 1948 graduate of Bryn Mawr School and studied theater at Finch College in New York City.

After graduating from Finch in 1950, she worked in New York as a production assistant for several Broadway producers.

Ms. Denny returned to Baltimore, married and raised her family of five children against a backdrop of mental illness, which she didn't shy from talking about.

For 22 years - since the establishment of the Hopkins' mood disorders symposium - Ms. Denny hoped her voluntarism would help psychiatry's outlook toward bipolar disorder.

"And her willingness to talk about having bipolar illness - she does so to a degree unusual even in this day and age - advances the cause," read a profile of Ms. Denny in a Johns Hopkins Department of Psychiatry newsletter.

"Mental illness has been a part of my life since birth, probably in utero, even," Ms. Denny said in the interview. "I don't ever remember a time without it. The last thing I wanted when I was 18 was to admit I had a problem."

Ms. Denny said she used her theatrical training to mask bipolar disease.

"But I couldn't hide it when I was married. You couldn't do that with five children under the age of 7, when you were in and out of treatment," she said. "They all knew what their mother was going through."

After Ms. Denny was divorced from her husband, Irwin Cromwell, she returned to her maiden name.

In addition to her work at Hopkins, where she was trained as a support group leader in bipolar disorders, Ms. Denny was an active supporter of Depression and Related Affective Disorders Association.

She was a member of the Mental Health Players and volunteered at Sheppard and Enoch Pratt Hospital. She also co-led a church-based volunteer peer support group.

Ms. Denny, a former Ruxton and Cross Keys resident who had lived at the Brightwood retirement community in Lutherville for nearly 18 years, never lost her love of the theater.

She had been a founder of the old Baltimore Actors Theater Conservatory and later became a member of the original board of Center Stage, which was founded in the early 1960s.

Besides her work as a trustee, Ms. Denny was a box-office volunteer and member of the theater's women's committee.

"I've known Joanie since 1966 until now - that's more than 40 years - and what comes to mind was that she was absolutely caught hook, line and sinker by the theater," said Peter W. Culman, former Center Stage managing director. "She had a certain exuberance and, as we say, she was a bona fide theater rat."

Mr. Culman said that Ms. Denny and the late actor David Rounds, who had performed at Center Stage, became close friends.

"He'd come to Baltimore to see Joanie when she was having problems and, two weeks before he died, she spent several days with him. She was close to him both on and off stage," he said.

Mr. Culman praised Ms. Denny's deep appreciation of Center Stage's actors, designers, directors, backstage personnel and volunteers.

"Theater was important to her and she'd do anything to see a good production at Center Stage, and made sure that all of those involved were in sync and did the best job possible," he said.

"No job was too menial for Joanie, whether it was stuffing envelopes or filling in at the box office. You name it, and she did it. She did whatever needed to be done," Mr. Culman said. "It was always very inspiring."

Mr. Culman said that Ms. Denny had devoted her life for more than four decades to the theater. "And she did this through the darkest of personal time," he said.

Reflecting on her bipolar condition, Ms. Denny said in the Hopkins interview, "This illness nearly ruined my life in many ways. But if you can give back in some manner - of yourself or with money - it helps. It really does bring joy."

She was a communicant of the Episcopal Church of the Redeemer, where a memorial service was held Jan. 16.

Surviving are three sons, Peter C. Cromwell of Cockeysville, Robert O. Cromwell of Phoenix, Baltimore County, and Walter D. Cromwell of Center Conway, N.H.; two daughters, Sally C. Grissom of Merritt Island, Fla., and Emily O. Cromwell of Cornish Flats, N.H.; and nine grandchildren.