Psychoanalysis has, in Hartmann's ego psychology, a description of the areas of mental functioning that engage reality. Medication affects these same areas of mental structure. Different medications have different specific effects on ego functioning, and therefore impact in specific ways on the structure of severe mental illness. This chapter describes observations about the exact locus of different medication effects on different ego functions, and therefore on psychic structure in the different illness structures of psychosis and near psychosis. Neuroleptic medications reinforce boundaries and allow more flexibility in the day residue's relationship to its own symbolic alteration. This chapter covers some specific ego functions, and then discusses specific defenses in affective illness as affected by medication. Neuroleptic medication has a quite variable effect on thing presentation quality in near psychosis. In summary, psychotropic medication in mental illness strengthens the ego for conflict repression, conflict integration, conflict adaptation in reality, and conflict resolution in psychoanalysis.