The "duty to protect" doctrine heralded by the Tarasoff decision seeks
to prevent physical harm to third parties by psychiatric patients. Recent
court cases have mandated the testimony of a criminal defendant's
psychotherapist both about the Tarasoff warning itself and about
confidential treatment information that was associated with the warning.
One court further ruled that some clinical sessions were not psychotherapy
and therefore were not afforded the protection of psychotherapist-patient
privilege. The continuing erosion of confidentiality has resulted in
psychiatrists and other mental health professionals becoming prosecution
witnesses at the criminal trials of their own patients.