Consultatie, onderwijs en bij- en nascholing in de filosofie en ethiek van de zorg, geneeskunde en psychiatrie

DIversity in psychiatric DIagnostics (DiDi-study)

Al langer loop ik met het idee rond om een (kwalitatief) empirisch onderzoek uit te voeren naar diagnostiek als concept in de psychiatrie. Onderstaand voorstel kon rekenen op steun van ZonMW, ze vonden zowel de opzet als mijn cv goed. Het onderwerp paste echter niet in de call van dat moment. Interesse? Ideeën voor financiering?


Depressive disorders are commonly accepted to be heterogeneous. Researchers try to discover specific profiles based on epidemiology and big data, trying to unravel different types of depression, relevant for new insights into classification, treatment and/or prognosis. This heterogeneity is not only related to patient, time and symptom dynamics, but also to psychiatrist factors. It is often said in the field that “when five psychiatrists are asked for a diagnosis, seven different diagnostic conclusions will be drawn”.

(Inter)national guidelines on the diagnostic process are inconsistent. The DSM has been developed to provide criteria to classify diagnoses and to give psychiatrists a joint nomenclature. However, concepts such as mood reactivity, objectifiable sombreness and affect modulation are relevant aspects for many psychiatrists in diagnosing depressive disorder, yet these concepts have not been included in the DSM criteria.    

The aim of this study is to map and evaluate the diversity of the diagnosis of depression. It is a quest into the nature and significance of the concept of diagnosing depressive disorders.   


This research focuses on the diagnostic process as performed in daily psychiatric care practice in the Netherlands, concerning depression-related symptoms to unipolar major depressive disorder. The study involves both an empirical dimension and a normative dimension.

What exactly do psychiatrists do when diagnosing depressive disorder or excluding that diagnosis and how does this relate to scientific literature on (depressive disorder) diagnostics? Can or should there be room for variation in diagnosis because of subjectivity and tradition, which can offer a basis for intersubjective investigation and dialogue?


The objective of this study is to describe and reflect on how psychiatrists actually diagnose depressive disorder or exclude it.

Research questions

- What do Dutch psychiatrists consider to be the nature and significance of the diagnostic process for depressive symptoms and how do they do this in their daily practice?

- How does the above relate to the current guidelines, standards and insights within scientific literature?

- Which conclusions can be drawn based on these results from a normative perspective and which recommendations can be formulated for psychiatrists diagnosing and treating depression?


This inductive research study will use a three-phase qualitative and responsive methodology. Phases will be performed partly parallel. This creates an iterative and emergent process in which data collection, analysis and literature research come together in a responsive mixed-methods design.

The first phase is a literature search. Part 1 is a text analysis of international (leading) guidelines on psychiatric evaluation, diagnosis and classification of depressive disorder. Part 2 is (an update of) a systematic review of literature on psychiatric evaluation, diagnosing and classification in unipolar depressive disorders with MeSH-terms in PubMed conform consort guidelines. 

The second phase is a file study. We will use patient files that will be examined twice on the same symptoms by different psychiatrists. There are three settings in which these ‘double examinations’ are quite often performed: in an academic hospital setting because of second opinions, in the criminal setting because of accountability issues (Pro Justitia NIFP), and in the administrative law setting because of appeal cases concerning incapacity benefits. Via lawyers, NIFP, patient organisations and social media patients with ‘double examinations’ will be asked to provide informed consent to obtain their medical records. In this purposive sampling process, we aim to obtain 50-70 double diagnoses medical record files for text analysis.      

Phase three is the data collection through (individual and focus group) interviews with psychiatrists to reflect on the results in the two other phases, using (video) vignettes. In the study population we strive for homogeneity on these issues and heterogeneity concerning work setting, seniority, gender and other relevant factors described in literature. We aim for 24 participants to achieve saturation on relevant coding. Grounded Theory Approach will be used for analysis.   


This project will produce new insights into the diagnostic process as used in Dutch healthcare practice, with depression as a case.

First, this will result in more knowledge on heterogeneity and diversity in diagnosing. To evaluate the variety and to differ between randomness and customization, the process of diagnosing must be understood first. Second, these new insights will result in an umbrella-guideline on the diagnostic process to streamline and improve diagnostic competencies in psychiatric practice. Third, this project will generate information on whether and how the diagnostic process and referral to psychiatric care is executed. This study is therefore relevant from the perspective of social responsibility (‘rechtmatige en passende zorg’).