Soortgelijke stoornissen. Over nut en validiteit van classificatie in de psychiatrie

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders was published in 2013. This manual classifies all known mental disorders and provides operationalized criteria for their diagnosis. The goal of this manual is to facilitate communication, treatment and research with reliable and valid diagnoses. This article will provide a study of what this diagnostic validity actually entails. Firstly, it will include a discussion of the different conceptions of validity that have appeared in the literature so far. To decide between these different conceptions, diagnostic validity will be defined as ”picking out a natural kind’. Secondly, two different accounts of natural and psychiatric kinds are examined, namely, essentialism and pragmatism. Both of these will be rejected in favor of conceiving natural kinds as causal-epistemic kinds. Thirdly, it is argued that the multidimensional complexity of psychiatric disorders does not exclude the possibility of psychiatric kinds being natural kinds. However, pragmatic considerations in classifying disorders have meant that the DSM most likely does not distinguish causal-epistemic kinds very well. I argue that the need to have a single classification both for clinicians and researchers and the priority given to reliability rather than validity has ultimately compromised the diagnostic validity of the DSM.