The Ninth Circuit has ruled shrinks can't rat out their patients, even if the patient makes a dangerous or threatening confessions during therapy.

Although psychiatrists are sometimes required to report incidents to authorities that could lead to violence, an en banc panel ruled that prosecutors couldn't use testimony from doctors to help convict their patients.

"On balance, we conclude that the gain from refusing to recognize a dangerous-patient exception to the psychotherapist-patient testimonial privilege in federal criminal trials outweighs the gain from recognizing the exception," Judge Susan Graber wrote for the 8-3 majority.

"Although incarceration is one way to eliminate a threat of imminent harm, in many cases treatment is a longer lasting and more effective solution. A criminal conviction with the help of a psychotherapist's testimony is almost sure to spell the end of any patient's willingness to undergo further treatment for mental health problems."