More than 2,400 Kaiser Permanente psychologists, therapists, social workers and other mental health workers in Southern California have begun an open-ended strike over increased workloads and staffing shortages.

The National Union of Healthcare Workers said nearly 2,400 mental health workers launched the job action after Kaiser Permanente management turned down their proposals.

More than 100 Kaiser mental health workers picketed outside the HMO’s medical center on Sunset Boulevard demanding higher wages, more prep time.