Calm down.

According to Scotty Turner, this is the most useless phrase an officer can say when dealing with someone who is mentally disturbed.

“It tells the person that they aren’t worth listening to,” he writes. “… It tells the person that their concerns aren’t valid.”

In role playing exercises, Turner, the community education director for the National Alliance on Mental Illness (NAMI)-DuPage County, has police replace the phrase with one that gives the person options—for instance, “You can sit down and stop yelling, or we will need to physically escort you from the building.”

Turner trains law enforcement officials on how to interact with those having mental health crises. He answered questions about his work in a Reddit Ask Me Anything (AMA) session.

His goal is to help cops avoid violent or demeaning confrontations, and get people the treatment they need. A recent study from the LAPD found that of the 38 individuals shot by the department last year, almost half had documented signs of mental illness. Mental health advocates have called for more de-escalation training for officers that focus on slowing down volatile situations.

“Unless cops know about mental illness in the first place, then they have no tools to change what they’re doing,” Turner writes.

Here are some highlights from the AMA.

We can’t expect police officers to become certified psychologists, so what’s the goal for this type of training?

What type of mental illness is most difficult for officers to understand?

Why is “calm down” so ineffective? Are officers generally more knowledgeable about mental illness than they were in the past?

Police can do what they can to de-escalate situations, but there’s a fundamental lack of public resources to help people with mental illness. What is an alternative to the current system we have?

If a person knows they have a mental disorder, what can they do to help police officers understand their situation?

What mental health issues does the training focus on?

How can cops diffuse situations without violence?

See the full discussion with Scotty Turner in the original AMA.