Workers gathered outside Kaiser hospitals in San Diego and Los Angeles counties Monday morning, launching what is to be an “open-ended” strike of Kaiser mental health care workers throughout Southern California.

More than 2,400 Kaiser Permanente psychologists, therapists, social workers and other mental health workers in Southern California began an open-ended strike Monday over increased workloads and staffing shortages that their union said have created a “substandard” system of care.

The labor dispute comes one year after Kaiser reached a $50 million settlement with state regulators who said the health care giant's mental health care system lacked adequate staffing that caused lapses in access to care for patients,