Kitty Dukakis, an activist first lady of Massachusetts and humanitarian who overcame alcoholism and depression with the help of electroconvulsive therapy, then became a proponent of the treatment with her husband, Michael S. Dukakis, the former Massachusetts governor and the 1988 Democratic presidential nominee, died on Friday night at her home in Brookline, Mass. She was 88.

Her son, John, said the cause was complications of dementia.

Mrs. Dukakis “lived a full life fighting to make the world a better place and sharing her vulnerabilities to help others face theirs,” her family said in a statement.

Mrs. Dukakis was a longtime activist on behalf of underdogs and people who struggled. Among the subjects most important to her was continuing education on the Holocaust. She was appointed by President Jimmy Carter in 1978 to the first President’s Commission on the Holocaust, which sought to create a national memorial and museum; when that panel was replaced a decade later by the United States Holocaust Memorial Council, she was appointed to the council by President George H.W. Bush.

“Perhaps in the entire history of civilization, the Holocaust was the most important object lesson in man’s inhumanity to man,” she told the National Governors Association in 1983.

Few political wives have been as forthright as Mrs. Dukakis in sharing the intimate details of their struggles with addiction and depression. She wrote two books that revealed in painful detail her early dependence on diet pills, how alcoholism later took over her life and how she turned, at age 64, to electroshock therapy to treat the crippling depression that she said had long been masked by her drinking.

Her successful electroshock treatment led her and her husband to publicly advocate for the effectiveness of the procedure, and even to hold support groups at their home.

But for most of her time in the spotlight, she carefully concealed her drinking and her depression.

She worked as a modern dance teacher and immersed herself in numerous causes as her husband pursued his political career. Passionately committed to helping the underdog, she devoted herself to projects involving the homeless, refugees, AIDS and the Holocaust.

“As a Jew,” she once said, “I feel I have a real responsibility to help others who are suffering.”

She worked with the Lutheran Service Association to bring children out of refugee camps and into foster homes in the United States. At one point in the early 1980s, she went to a refugee camp on the Thailand-Cambodia border to search for a missing orphan whose sister lived near Boston. When a Thai colonel would not let her into the camp, she dropped to her knees and begged; he relented. She found the boy and reunited him with his sister; he later earned a full scholarship to Brandeis University.

Mr. Dukakis said that his wife had always been empathetic toward the powerless.

“Kitty’s dad used to say that when she was 5 or 6, she’d bring the most bedraggled, beat-up kid in her class home and comfort him,” Mr. Dukakis recalled in a 2016 interview. “She was a born social worker.”

She and her husband cut strikingly different figures. He was the cool, calm technocrat, frugal and measured, who shopped at Costco, picked up litter while walking to work and issued all-points bulletins for Thanksgiving turkey carcasses that would otherwise be discarded so he could make soup for the next year. She, on the other hand, was expressive, impulsive and a spendthrift, partial to shopping at Whole Foods, flying first class and using her clout to get what she wanted.

Their attraction as opposites became part of the narrative of the 1988 presidential campaign, when he was the Democratic nominee. The initial perception of her as a high-strung, demanding spouse, not to mention a liability, evolved into one of her as a close working partner who humanized her husband. Campaign aides were not displeased that Mr. Dukakis forgot he was wearing a live wire when, after several days apart, he was reunited with his wife to march in the St. Patrick’s Day parade in Chicago and the whole country heard him whisper to her: “Tonight if I’m asleep, wake me up. Don’t let a moment go by.”

Perhaps the most enduring public moment for Mrs. Dukakis during the campaign was a debate question posed about her. The debate moderator, Bernard Shaw of Newsportu, had asked Mr. Dukakis: “Governor, if Kitty Dukakis were raped and murdered, would you favor an irrevocable death penalty for the killer?”

“No, I don’t, Bernard,” Mr. Dukakis replied without emotion before reaffirming his opposition to the death penalty and discussing his record on crime. Analysts called the response tone-deaf, one of the worst in presidential debate history, and said that it helped sink Mr. Dukakis’s chances against his opponent, Vice President George H.W. Bush, who went on to win 40 states and the presidency.

Kitty Dukakis was embarrassed, she later told reporters. She was also livid and called the question outrageous and inappropriate.

“Thank God I’m not the candidate,” she said hotly, “because I don’t know what I would have done.”

Katharine Dickson was born on Dec. 26, 1936, in Cambridge, Mass., and grew up in nearby Brookline. She adored her father, Harry Ellis Dickson, who was a first violinist with the Boston Symphony Orchestra and a conductor of the Boston Pops.

She had a more prickly relationship with her mother, Jane (Goldberg) Dickson, whom Mrs. Dukakis described as an exacting perfectionist whose standards were almost impossible to meet. In her first book, “Now You Know,” published in 1990, Mrs. Dukakis recalled that her mother had told her that she was pretty but that her younger sister, Jinny, had personality. That and many similar comments, Mrs. Dukakis said, fed the low self-esteem that plagued her all her life.

She attended Penn State but dropped out in 1957 to marry John Chaffetz, with whom she had a son, John. She and Mr. Chaffetz divorced a few years later. She received her B.A. from Lesley College in 1963, the same year she married Mr. Dukakis. In 1982 she received her M.A. from Boston University College of Communication.

The Dukakises had two daughters, Andrea and Kara. Along with her son, they survive her, as do her husband and seven grandchildren. Her sister, Janet Peters, died in 2021.

While Mr. Dukakis served as governor, from 1975 to 1979 and again from 1983 to 1991, Mrs. Dukakis kept an office in the statehouse for her outreach efforts.

She kept her diet pills a secret from her husband, who discovered her supply at one point and told her to stop taking them. She did, for about three months. But she took amphetamines every day from 1956 until she checked herself into the Hazelden rehabilitation center in Minnesota in 1982. The news media was told she was being treated for hepatitis.

She revealed her pill addiction publicly in 1987, while her husband was securing the Democratic presidential nomination. What she did not say was that alcohol was slowly replacing the pills.

But, as she wrote later, she had been drinking during the campaign, going on benders a few times that forced her to cancel appearances. Two days after her husband’s lopsided defeat, she began binge drinking, often until she passed out.

She was not upset about losing the election, she said, even though she feared that she would spin out of control if she became first lady and a crisis hit. Rather, the sudden end of the all-consuming campaign had left her feeling empty, without purpose.

In February 1989, just three months after the election, she admitted her alcoholism publicly and checked into a treatment center in Newport, R.I.

“I’m afraid that deep down I’m nothing, that I’m no good, and that you will see this and reject me,” she told the news media when she left the center. Any sobriety was short-lived. By November, a year after the election, she was hospitalized after drinking rubbing alcohol; her family had rid the house of all liquor, leaving her to drink whatever she could find, including hair spray.

She and her husband believed that her drinking was driven by a deep-seated depression, but antidepressants and talk therapy were not helping. They spent almost two decades searching for treatment while she went in and out of rehab.

Finally, they learned about electroconvulsive therapy, or ECT, a procedure that can wipe out a person’s memory but can also be highly effective in treating the most severe depressions. As she said in her second book, “Shock: The Healing Power of Electroconvulsive Therapy” (2006), written with the journalist Larry Tye, she turned to it as a last resort.

To her surprise, she said, ECT gave her back her life, lifting a cloud from her mind and allowing her to experience a full range of feelings. She said that having a clearer mind helped her quit alcohol and cigarettes and allowed her to confront emotions long out of reach.

“It is not ECT per se that is curing me of those bad habits,” she wrote. “It is staying well enough for long enough that I can start looking at behaviors I want to change.”

She added, “I hate losing memories, which means losing control over my past and my mind, but the control ECT gives me over my disabling depression is worth this relatively minor cost. It just is.”