Some aver that the biopsychosocial (BPS) model is not fully scientific because it lacks a method to produce BPS information. To resolve this criticism, I propose that we think in terms of general and specific BPS models. What most understand to be the model is the general BPS model. It simply indicates that all patients be understood in biological, psychological, and social terms without specifying a method or sources of BPS information. Its fundamental function is to guide medicine away from the effete, 17th century disease-only model in clinical care, teaching, and research. Considerable population-based research data also support its scientific status. Less well understood, but of greater relevance to the clinician, is the specific BPS model, which describes the BPS features unique to an individual patient. The specific model, however, requires an interviewing method to achieve this, the method critics believe lacking.
In this article, I review how medical communication scholars have established a method to acquire individualized BPS data on each patient. Research identified the patient-centered interviewing (PCI) method to do this. After much progress over several decades, the field was able to test the PCI in several randomized controlled trials—and confirmed it to be evidence-based. Therefore, by definition, because the patient-centered interview defines the specific BPS model in each patient, the model itself is evidence-based. This means we now can, for the first time, identify a scientific BPS model for every individual patient. Joining this scientific support with much existing data for the general model, we now have a fully scientific BPS model.