Right now, the field of psychology is replacing phrenology and faith healing with biochemistry. And, you know what, good riddance!
Freud's era was one that underestimated the complexities of analysing, well, complex systems, where phenomena arise not out of the interactions of more-or-less pure entities like in Newtonian physics, but as the chaotic aggregation of heterogeneous subsystems, like what we now understand many biological processes to be.
I think the field today is doing what mathematics had been doing a couple ago; back then mathematicians realized that calculus was on shaky foundation, and developed tools to set mathematics on a firm logical and set theory foundation. Likewise, psychology is investigating neurology and trying to find a firm foundation in it.
On the other hand, the potency of well defined, minimal theories is unarguable.