Psychotherapist Says Jan. 6 Rioters Had Raging 'Biden Derangement Syndrome'

Jonathan Alpert is gonna catch even more heat for this ... after pissing off folks by asking if "Trump Derangement Syndrome" is real, he's now saying the Jan. 6 Capitol rioters suffered from "Biden Derangement Syndrome."

The renowned psychotherapist joined us on "TMZ Live" Thursday and we asked him about TDS ... this on the heels of a TDS column he published in the Wall Street Journal.

Jonathan says he's seen lots of patients who were so consumed with anger and worry over Trump that they couldn't relax or sleep ... including one woman who he says couldn't enjoy a family vacation to Europe because she couldn't get her mind off DT.

The interesting part, though ... is Jonathan says Democrats aren't the only ones dealing with this ... he says the Trump supporters who stormed the Capitol when Biden's 2020 election win was being certified by Congress had "Biden Derangement Syndrome."

We asked Jonathan if Trump has BDS ... given how much Trump talks about Biden. Jonathan says it's not the same, because Trump actually went toe-to-toe with Biden in an election.

Still, we challenged Jonathan on Trump and BDS ... just like we pushed back on him when he suggested folks bury their heads in the sand for the next couple years if they can't stomach Trump.