To begin with, I will say two things: Gross’s central thesis is this: the psychology of the unconscious is the philosophy of revolution. Second: for him, and contrary to Freud and his circle, the normal subject is the most pathological. Add: its maxim is summarized as follows: do not violate or let yourself be violated.

I am not sure but I remember reading somewhere he became a psychotic person ...? Is this true?

Maybe. He was an addict to morphine and cocaine (like Freud, of course). And an anarchist. The first analyst from left, extreme actually. Before Reich, of course. Freud send him to a manicomio, and Jung tortured him. But Gross was, first, Jungs analyst, and friend. And, as well, he teach the methode to this good man, Herr Jung, and to Mr. Jones.