Critical Psychology is not really an division of psychology but more an methodology by itsself.
Founded in the 70th in Berlin at the FU-Berlin it tries to reformulate the traditional psychology on an unorthodox marxistic base.
The big merit of the Critical Psychology is an approach to get to grip whith the social and the historical conditionalyty of the human being.
On of the most important Books is the "Grundlegung der Psychologie" by Klaus Holzkamp (Frankfurt a. M. 1983) the theoretical head of the Critical Psychology.
A couple of years ago the departement of Critical Psychology at the FU was closed and was added to the traditional Psychology Departement.
But this idea of psychology is still alive and topical. More information about Critical Psychology under http://Kritische-Psychologie.de