Zooming in, as is often done with the biomedical approach, means staying within the paradigm of your own discipline. This is practical, because it means that your points of departure are quite clearly related to each other and can be shared with other practitioners in your discipline, since they all belong to the same paradigm—that of the exact sciences. Zooming out, as is the intention when using the BPS model, inevitably means also scrutinizing your own way of looking at things. Moreover, the BPS model combines the exact sciences paradigm of biology with the paradigms of the social sciences and humanities, which also differ from each other. Because findings from the exact sciences paradigm are easier to generalize internationally—unlike groups of people, iron molecules behave in exactly the same way in Japan as they do in the Netherlands—and research aims to be as universal as possible, in terms of research-based evidence, there is a hierarchy, with the exact sciences at the top. However, as far as relevance is concerned, it is often the other way round: in controlled laboratory conditions, you can know something for sure, but human beings do not live in such controlled conditions. If you zoom in, you see less but with greater certainty and generalizability. If you zoom out, you see more, but not as clearly.

While using different perspectives improves the quality of diagnostics, the improvement depends to a significant extent on the quality, background, and personal characteristics of the person carrying out the diagnosis. This subjectivity is at odds with the aim enshrined in scientific tradition to achieve objectivity in terms of “replicability” and “independence from the observer.” In the case of syndrome diagnoses and behavioral or mood disorders, it is almost impossible to meet these criteria, and treatment and prognostic implications, for instance, are always limited, because often understanding progresses, including in terms of treatment goals. All these changes have an adverse effect on repeatability and therefore also on reliability in the scientific sense. In practice, there are several strategies for dealing with this problem. You can systematically check all the different lines of enquiry; the lists that are often abundantly available are very handy when doing this. You can also, more or less artificially, stick to the goals set at an earlier point to determine the effectiveness of the interventions on the basis of the results attained, as is often done in intervention research. You also can be guided by intuition, matching your questions to the conversational flow or to the treatment in the broader sense. As you proceed, observing and identifying, you will slowly but surely arrive at more and more clear-cut working hypotheses, which you can then test by asking further questions. However, by definition strategies are in themselves context dependent and can therefore change depending on the situation. The diagnostic process imitates human observation: the first impression is the diagnosis, which is then tested or, more often, substantiated. Gradually the health professional finds out who the other person is, where the problems come from, why previous solutions were not successful, etc. In themselves, syndrome diagnoses are easy to make, but unfortunately they provide little insight, let alone guidelines for treatment. These must be gained in the process of working with the patient.

When it comes to syndrome diagnoses, the name plays a special role. If something has no name, it does not exist and is therefore not medically or socially acknowledged. To put it differently, the fact that there is a diagnosis contributes greatly to the strength of the rationale behind the way a certain disorder is seen in various circles. For the patient, a plausible rationale is often a prerequisite before he or she is prepared to undergo treatment at all. For the health professionals involved, a rationale of this kind is an ideal guideline for their actions. The patient wants plausibility; the health professional wants an evidence base. These two can be contradictory. In practice this is usually resolved by mentioning the syndrome diagnosis in passing, saying, for example, “this is popularly known as PMS.” This provides the recognition the patient needs at the beginning of the process, and gradually this terminology can be abandoned if this seems appropriate. The same principle can be applied to “standard” follow-up tests. Even though you know that a certain scan will not help to find a sound diagnosis, it may be a prerequisite for the patient to feel they are being taken seriously. Formal discussions with one’s own fellow practitioners are trickier. There are plenty of “conservative” professionals who dismiss any kind of “liberal” approach to diagnostics or treatment as quackery. The question that then arises is what a person sees as the function, task, or role of diagnostics or even of medicine. The point of departure we take is that medicine is a practical profession whose primary purpose is to care for the patient. Obviously this does not exclude a role relating to more general knowledge, that is, in research, but it does highlight this book’s position.