Cultural Marxism is a minimal side effect with maximal societal damage potential of “Leftardation”, which is a single word definition of “Liberalism is a mental disorder”
I like “Leftomentia” or “Leftomanic Syndrome” myself. “Leftophrenia” might work, too, but there are degrees to that. Extreme form is “paranoid leftophrenia.” Sufferers include Dennis Kookcinich and that waddling tub of lard from Flint, aka Mikey the Moron.