A revisionist model for treatment-resistant and difficult-to-treat depression.

Objective: The aim of this study is to consider limitations to the heuristics 'treatment-resistant depression' (TRD) and 'difficult-to-treat' depression (DTD) and to offer a revisionist model.

Methods: A number of limitations to the two constructs are noted, particularly the risk of each positioning clinical depression as an entity and then applying a linear sequencing management model.

Results: Arguing that clinical depression is heterogenous in nature (with categorical and 'fuzzy set conditions), in cause and in response to treatment, allows an alternate model for addressing depressive conditions that are not readily responsive to treatment. A skeletal model for proceeding is offered for consideration and development.

Conclusion: If such a model is accepted, then differing criteria for defining treatment resistance and treatment failure might be generated for differing depressive conditions, and condition-specific sequencing algorithms (embracing drug and non-drug strategies) developed for their management.