Abstract
Three important questions can be asked about validating psychiatric classifications: what can be validated; how can it be validated; and what does validating something accomplish? The most common answers given by psychiatrists would likely be that we validate disease entities, we do this by finding causes or corroborative factors, and validating a disease entity proves its reality. These are not the only possible, or necessarily best, answers to the questions, as amply demonstrated by the recent volume Alternative Perspectives on Psychiatric Validation which contains 15 diverse papers on validity. Psychiatry is currently facing a crisis of confidence because more than 30 years of investigation has not established causes or corroborative factors for most psychiatric classifications, leaving them unvalidated. This volume comes at an important time, showing flaws with current approaches to validation and providing alternative approaches. Additionally, these questions can be important for historians, since notions of real disease entities causing symptoms are sometimes employed by historians of psychiatry.
Most papers are philosophical, but papers by Aragona and by Zachar and Jablensky are primarily historical. Aragona gives a history of DSM, arguing against the typical received view which sees DSM-III onwards as highly discontinuous with DSM-I and DSM-II. He shows that reliability was considered an important problem long before the 1970s, and that neo-Kraepelinian assumptions about disease entities were present in those early editions. Rather than introducing a radically new way of conceptualizing the tasks of classification, DSM-III merely placed more emphasis on reliability and on finding disease entities than had previous editions. In his view the most important DSM-III change concerned how psychiatric classifications are validated; in DSM-III there was a new expectation that one day laboratory studies would find causes of psychiatric disorder. The failure of this project has led to the current crisis of confidence over the validity of psychiatric classifications.
Zachar and Jablensky discuss philosophical assumptions underlying DSM approaches to validation. They show how DSM-III was based on an uneasy combination of scientific realism and logical positivism which supposedly would see disease entities validated through finding causes. They describe how recent projects such as Research Domain Criteria (RDoC) might lead to alternative philosophies which reject disease entities, situating the current crisis as another swing in wider historical oscillations between disease entity and non-disease entity approaches. These two papers highlight shifting historical approaches to validation while showing some surprising commonalities in underlying assumptions influencing approaches to validation.
Other papers in the collection offer alternative views on what can be validated, especially on the relationship between validation and values. Murphy sees validation as purely about validating out there waiting to be discovered causes. He argues that psychiatric classifications are value-laden and so cannot be validated, but only correlated with causes. In contrast, Loughlin and Miles take the value-laden nature of psychiatric classification as meaning that validation requires an adoption of moral realism. Sabbarton-Leary, Bortolotti and Broome adopt a middle ground. They consider biologically-based psychiatric disorders to be natural kinds, while conditions without biological causes cannot be natural kinds but can be a different form of kind. They suggest calling these value-laden psychiatric classifications mental harms rather than mental illnesses. All these papers show that validation needs to take seriously the role of values in formulating psychiatric classifications; each paper provides a different answer to how validity and values relate.
Many papers offer alternative views on how psychiatric classifications can be validated, challenging typical focus on finding causes and corroborative factors. Sabbarton-Leary, Bortolotti and Broome’s demarcation between biologically and non-biologically based psychiatric classifications leads them to argue that each needs validating in a different way. This general claim is expanded in Markova and Berrios’s paper and in Philip’s paper. Markova and Berrios highlight the limits of neuroscience, arguing some symptoms involve an inherently subjective element not amenable to brain localization, reducing the applicability of neuroscience to provide validation. Philips highlights how validity involves non-empirical assumptions about causation, showing that current biomedical approaches involve notions of causation not ideal for psychologically-based classifications. Jacobs and Krueger argue that when psychiatric classifications have high co-morbidity it will be necessary to validate clusters of psychiatric classifications rather than individual disorders. Stoyanov, Borguard and Varga’s paper on neuroscience and Cloninger’s paper on personality are rich in scientific detail. Both describe the methodological limitations of, and methodological alternatives to, current approaches. These papers challenge simplistic notions of validation as simply locating causes or corroborative factors.
Many papers offer alternative views on what validation accomplishes. Validity is typically seen as independent of context and pragmatic usefulness. Keeley challenges this, arguing that what is measured by validity depends upon background assumptions. Different situations require different assumptions – which are typically pragmatically chosen – making validity context dependent. Rodrigues and Banzato argue that both the reality and usefulness of a disorder can be validated. Sometimes a focus on either reality or usefulness will yield the same psychiatric classification, but sometimes this will not be the case. This can potentially result in there being two different but valid psychiatric classifications. Stoyanov and Aragona discuss the challenge of employing multiple types of evidence (biological, psychological, environmental) for validation, suggesting that each type only validates to its own context but that combining different context-dependent validations can provide information on context-independent reality. These papers challenge typical pictures of validation as telling us about a mind-independent reality; some argue that validity is always context dependent, others arguing that this need not always be so.
The collection is recommended for the many perspectives provided on diverse aspects of validity, with philosophers, historians and scientists challenging existing assumptions and methodologies. The papers often substantially disagree but this is a strength of the volume: after focusing for so long on biological causes without substantial result, we need a wide-ranging discussion rather than rushing to adopt RDoC. Historians who see a dichotomy between real disease entities and social constructivism may benefit, since the volume shows how alternatives to typical disease entity approaches can still involve reality. It is readable and will be accessible to historians, clinicians and scientists.