When Donna Mateer was 14, she walked into a Whittier department store, put on a wedding dress, and strolled out. Store security quickly detained her for shoplifting. It was her first arrest, and an early sign of the mental illness that has afflicted her ever since.

When Mateer was in her 20s, she worked at McDonald’s for a month, according to her sister Debbie Gish. It was the only job she ever had.

In 1994, when she was in her 30s, Mateer moved to San Francisco to live with Gish. Nearly a decade of chaos ensued. The sisters recalled Mateer hammering away on the piano in the dead of night. But it wasn’t just loud music — deep in a depressive episode, Mateer tried to take her own life by swallowing pills. At the hospital, she had her stomach pumped and was diagnosed with bipolar disorder. For the next 10 to 15 years — neither sister quite remembers the timeline — Mateer cycled through filthy board-and-care facilities and single-room occupancy hotels.

Then, sometime in the 2000s, she arrived at the Behavioral Health Center at Zuckerberg San Francisco General Hospital and, for the first time, found stability. Mateer said the BHC staff truly care about her. They make sure she takes her medications and eats during her depressive episodes, but they also play guitar for residents and make them laugh.

But soon, Mateer, 66, and the facility’s 81 other residents will have to move. As part of Mayor Daniel Lurie’s plan to tackle the homelessness and drug crises, the Department of Public Health is converting the center into a mental health rehabilitation facility to treat people in crisis and moving current residents to facilities outside the hospital, including two in Hayes Valley that have yet to open. Unlike the current center, in which one floor is a locked ward, the new center will consist completely of locked beds for patients who need round-the-clock psychiatric care.