In the last years of her life, Cabot suffered from depression and suicidal thoughts, and was prey to a wide range of irrational, powerful fears. She was under a licensed psychologist's care, but the psychologist found her so troubled and ill that the sessions became "emotionally draining." Cabot became increasingly unable to care for herself; the interior of her home was littered with years of trash, and spoiled food lay everywhere. In late 1986, Cabot's mental health deteriorated significantly. Despite the squalor of the home's interior, Cabot still maintained a "adequate" income despite having retired from acting, largely due to real estate investments and her fascination with vintage cars, which she regularly acquired, restored, and resold.
On December 10, 1986, Cabot's 22-year-old son, Timothy Scott Roman, beat her to death in her home in the Encino neighborhood of Los Angeles, with a weightlifting bar. He was charged with second-degree murder.