Residual phase refers to a period in the course of schizophrenia, following the active phase, in which there are continuing indications of disturbance, evidenced by the same kinds of behaviors that characterize the prodromal phase.
Residual phase is also called Residual type, the "filler” category in the disease formulation of schizophrenia; characterized by improvement to the extent that schizophrenic features can no longer be ascertained. The Residual phase follows the Active phase in the disease process.
Other /More definition:
Residual phase refers to a period in the course of Schizophrenia, following the active phase, in which there are continuing indications of disturbance, evidenced by the same kinds of behaviors that characterize the prodromal phase.