Brutalist architecture & housing projects have been blamed, at least since Jacob's Life and Death, for the disintegration of neighborhoods into ghettos and blighted areas. So I think the claim seems plausible.

Almost certainly hyperbole, but architects -- especially of that era -- do have a habit of making surprisingly grandiose estimates of their work's social effects.

Of course, it's unlikely that any successful architect not working in set design for vampire movies would deliberately set out to depress people into suicide.