Kennedy, the youngest son of the longtime Massachusetts Sen. Ted Kennedy, writes in The Washington Post
that the rhetoric surrounding the 2016 election discourages anyone suffering mental health issues from seeking help.
"With all of this damaging rhetoric floating around in our national political discourse, especially what we hear from and about Trump, it's no wonder that people remain silent and the suffering continues," Kennedy wrote. "So if you've got a criticism about Trump's temperament, fine. But let's eliminate the name-calling and grade-school bullying. As Michelle Obama put it, 'When they go low, we go high.'"
Kennedy, who himself struggled with mental illness and addiction, co-authored a book on his experience called "A Common Struggle."
Kennedy said he's no "Trump fan" and wants to stop him from becoming president, but not by using demeaning language.
"There's a lot to criticize about the policies, ideas and ideology of the Republican nominee," he wrote. "We can reject Trump without resorting to making baseless diagnoses of his mental health."
In the op-ed, he cited his late uncle's President John F. Kennedy's declaration, the Community Mental Health Act of 1963, that says those with mental illness "need no longer be alien to our affections or beyond the help of our communities."
He said America needs to elect lawmakers who understand the importance of mental health.
"We need to elect policymakers who believe it's right to treat diseases of the brain the same as illnesses of the body, like diabetes and heart disease," he wrote. "Calling people crazy doesn't further that goal, and slows our efforts toward equality."