Abstract

'What constitutes a disease?' This issue is as old as medicine. The respective debate in psychiatry centres around the definition of 'mental disorder'. In the last decades an impressive development of sophisticated research techniques, efficient therapeutical options and, more generally, an increased diversity of psychiatric conceptualization took place worldwide. This urgently calls for a thorough reflection on – and, if necessary, adaptation of – nosological concepts, not least in respect of the future identity of our field.
With reference to the recent literature the lecture will outline chances and limitations of the following lines of thought:

• Reification: Mental disorders as 'things'.
• Operationalization: Descriptive psychopathological criteria and diagnostic algorithms.
• Idiography: Subjective (including interpersonal) experiences as predominant elements of psychopathology.
• Denosologization: Research technology- and data-driven approaches (e.g. Research Domain Criteria [RDoC], machine learning).

21^st-century psychiatry will have to acknowledge that a multi-perspective-approach is mandatory when it comes to mental disorders. There are, however, two caveats: First, multi-perspectivism carries the risk of splitting the field into unrelated domains that tend to drift apart and to undermine psychiatry‘s (already not too stable) identity as a distinct medical field. Second, it may unjustifiably suggest that overarching topics which cannot be addressed by one perspective only are of minor scientific relevance (e.g. mind-body-relationship, personal autonomy and responsibility). One option to tackle such pitfalls, advocated by seminal authors like Karl Jaspers, Arthur Kronfeld and Werner Janzarik, is to enhance the status of psychopathology, enabling it to encompass the first-person- as well as the second- and third-person-accounts. It could then serve as a sustainable link between various perspectives in psychiatry. Most notably it could bring philosophical issues as mentioned above closer to actual empirical research where they tend to be underestimated nowadays.
In summary, conceptual transitions in psychiatry have been and will be challenging tasks. But they are necessary and stimulating for the field, as long as they are situated within a framework that accommodates psychiatry’s person-centredness and its roots in diverse scientific traditions.