Sentence:  Freeman , Cameron and McGhie , in their description of the disturbances of thinking found in chronic schizophrenic patients , say , in regard to condensation , that `` the <WSD>lack</WSD> of adequate discrimination between the self and the environment , and the objects contained therein in itself is the prototypical condensation '' . 
Meaning of the word marked with <WSD> tags:  the state of needing something that is absent or unavailable