AP National Writer

Each time mental illness is cited as a possible factor in a high-profile mass killing, there’s a collective sigh among mental health professionals. Even as they see an opportunity for serious discussions of problems and remedies, they also worry about setbacks to efforts to destigmatize mental illness.

“Most people who suffer from mental illness are not violent, and most violent acts are committed by people who are not mentally ill,” said Dr. Renee Binder, president of the American Psychiatric Association.

According to federal estimates, there are more than 9 million adults in the U.S. experiencing serious mental illness in a 12-month span.

Binder says only a tiny proportion of them will eventually commit violence. “How are you going to identify them?” she asks. “It’s like a needle in a haystack.”