IN SPITE of substantial advances in the effective treatment of psychiatric illness, there is a growing perception among clinicians that those patients who present for inpatient care are more difficult to treat. The authors review the history of contributions about the patient who is difficult to treat and propose a new typology for characterizing acute, severe and complex dimensions of this cohort. They hypothesize first that patient difficulty cannot be conceptualized independently from the treatment context; and second, that treatment complexity leads to a specific strain between the on- and off-floor treatment staff, thus enhancing the perception of difficulty. Finally, the authors suggest innovations in the structure of the treatment environment that may facilitate treatment of these patients. These innovations operate especially in the area of reducing interstaff tensions and helping patients use rather than resist that treatment.