Lea Thompson and Others Offer Kristen Johnston Their Condolences After Her Sister's Death

Lea Thompson and Patricia Arquette were among the many people who offered their condolences to actress Kristen Johnston, who posted about her sister's death on Twitter on Tuesday morning.

In a tweet, the Third Rock From the Sun actress told followers that her sister died on Monday. "Yesterday my beautiful younger sister Julie lost her battle with addiction," she wrote, sharing a photo of the two together. "I know she's finally at peace. She had the best belly laugh in the world."

Thompson and Arquette were among the many fans and other celebrities who offered support for the actress after she tweeted that her sister had died. Thompson wrote that while she was sorry for the actress' loss, she was glad that Johnston had found recovery from her own struggles with addiction. "Cunning baffling and powerful. For sure," she tweeted.

Other celebrities that shared messages of sympathy for the Mom star included Special Olympics athlete Tank Schottle, actress Quinn Cummings, and actress Kiersten Warren, who shared a GIF with a flower offering prayers. Warren also responded to Johnston's memories about her sister's laughter. "The world is so much poorer with the loss of a good belly laugh," she wrote.

Comedians Judy Gold and Amy Phillips both retweeted Johnston with their condolences. "My heart is with you," Phillips tweeted.

Some fans and followers offered sympathy by sharing their own experiences with losing loved ones to addiction.

Johnston thanked her followers and colleagues for support she's received since her sister's passing.

Johnston has spoken publicly about her own struggles with addiction in the past, many of which she detailed in her 2012 book Guts. In a 2013 op-ed for The New York Times, she revealed that she'd been sober for over six years. She began SLAM NYC (Sobriety, Learning and Motivation), which intended to open the city's first addiction-recovery high school, according to The Times.

After getting sober herself, Johnston became an advocate for addiction and recovery nationwide. "Drugs are now the No. 1 cause of deaths in emergency rooms," the actress wrote in her 2013 op-ed. "A minuscule percentage of those who suffer can afford to get help, because most insurers refuse to cover treatment. We imprison those whose only crime is being an addict, and I can't even get the New York City schools to let my organization, SLAM, NYC, build a sober high school."

Johnston's manager did not respond to Newsweek's emailed request for comment.

Kristen Johnston
Kristen Johnston Signs Copies Of Her New Book "Guts" at Book Soup on March 18, 2013 in West Hollywood, California. Johnston tweeted that her sister had died after battling addiction on Monday. Getty/Gabriel Olsen/FilmMagic