The San Francisco jail system serves as a "default mental institution" due to the high number of inmates with mental health problems and needs better staffing, training and procedures for communicating and tracking information about inmates to handle the load, according to a Civil Grand Jury report released Thursday.

Nationally, almost two-thirds of jail inmates have mental health issues, while in San Francisco around 35 to 40 percent of inmates receive care from Jail Behavioral Health Services and around 15 percent are being treated for a serious mental illness. Health issues, mental illness and substance abuse problems are common among inmates, and 31 percent have been homeless within the past year.

"The crises in public health and social services has made the Jail an unintended provider of psychiatric and social services for the mentally ill and the homeless services the jail has neither the capacity nor the mandate to provide," the report states. "This increase of mentally ill and homeless inmates in need of health, psychiatric, and re-entry services further depletes the resources of the department."

Among the grand jury's recommendations are calls for Jail Behavioral Health Services to be staffed 24 hours a day, and crisis intervention and suicide prevention training for all staff that work with inmates.

The report focuses in particular on suicide prevention efforts, noting that suicide is the leading cause of inmate deaths nationwide. The risk is particularly high, seven times higher than in the general population, for those not yet convicted but awaiting trial.

The grand jury report also recommends better communication between arresting officers, sheriff's department staff and medical staff and tracking of inmate medical information. In addition, it calls for the establishment of a reliable method for family members of inmates to communicate concerns about mental and physical health to jail officials.

The sheriff's department had planned to improve mental health care in part by constructing a new jail with better facilities to replace an unsafe jail at the San Francisco Hall of Justice. However, the Board of Supervisors voted against that plan in December due to concerns that it emphasized incarceration over treatment and services.

Sheriff's department officials Thursday said they were reviewing the grand jury report and working with the jail replacement work group on plans for a new project. The working group is expected to complete a report before the end of the year.