to me it's more a matter of truth content. in the sense that marxism provides a radical knowledge base for social change, i believe that many aspects of freudianism are useful for identifying and challenging how a dysfunctional society fractures individuals.
one intriguing attempt to apply freudian concepts in something close to a "legitimate" scientific, clinical and socially analytic setting was adorno's work on "the authoritarian personality" in which he and others identified psychological underpinnings of regressive/reactionary social movements (e.g. anti-semitism, nazism, etc.)
michael "apparently no longer classifiable as neurotic by the medical profession" catolico