1. "[W]ithout substantial assurance of confidentiality, those requiring treatment will be deterred from seeking assistance."

2. "[T]he guarantee of confidentiality is essential in eliciting the full disclosure necessary for effective treatment."

3. "[E]ven if the patient fully discloses his thoughts, assurance that the confidential relationship will not be breached is necessary to maintain his trust in his psychiatrist--the very means by which treatment is effected."

Summary:

"Given the importance of confidentiality to the practice of psychiatry, it becomes clear the duty to warn imposed by the majority [i.e. Tobriner] will cripple the use and effectiveness of psychiatry. Many people, potentially violent--yet susceptible to treatment--will be deterred from seeking it; those seeking it will be inhibited from making revelations necessary to effective treatment; and forcing the psychiatrist to violate the patient's trust will destroy the interpersonal relationship by which treatment is effected."

Plus another factor: Risk of deprivation of liberty

"By imposing a duty to warn, the majority contributes to the danger to society of violence by the mentally ill and greatly increases the risk of civil commitment--the total deprivation of liberty--of those who should not be confined."

A net increase in violence:

"In short, the majority's duty to warn will not only impair treatment of many who would never become violent but worse, will result in a net increase in violence."