[Distinction between regression and retardation]

Retardation is an impairment of functioning, which has affected individual growth from the onset of life. Regression is a temporary developmental flaw which is more easily amenable to psychdynamic understanding and treatment. In reality both retardation and regression are interlaced in great complexity. The structural axis of the OPD system has for methodological reasons decided to assess both states separately. Once the developmental level has been assessed, the structural level can be determined. Difficulties of this procedure are discussed.