Progress in Psychiatry Requires a Marriage of Utility to Validity

The future of psychiatry depends on resolving the tension between use of discrete definitions of mental conditions for clinical diagnoses and researchers’ understanding of symptoms as occurring along continuums and with different dimensions, according to an article in World Psychiatry by Assen Jablensky, MD, of the University of Western Australia in Perth.

“The conceptual outlines of syndromes and putative disease entities tend to change with successive revisions of their classification, relative to their utility for predicting course, outcome and likely response to available treatments, even if their inner biological and psychological structure is not fully understood,” Jablensky wrote. “The latter, the quest for validity of our concepts, remains an open agenda.”

Despite scientific advances, psychiatrists still lack a way to clearly determine where normal variation becomes pathological and how symptoms relate to the underlying physical or genetic etiology of a condition. Instead, new findings continue to raise more questions, such as how some individuals with schizophrenia can recover while others cannot, despite having nearly identical symptomology or meeting the same diagnostic criteria.

In fact, schizophrenia provides a good case study in illustrating how psychiatry has not quite met the basic goals of constructing a set of principles and rules for classification of psychiatric conditions.  Despite the need to “identify internally cohesive clinical groupings based on established intercorrelations among symptoms and syndromes and patterns of course and outcome,” discordance among outcomes of schizophrenia and affective disorders defy attempts to develop consistent, reliable life histories of conditions.

Further, even distinguishing between schizophrenia and affective disorders remains fuzzy and resistant to fixed diagnostic criteria based on clear natural boundaries. And the difficulty in identifying and adequately describing sub-threshold cases of schizophrenia lends credence to the concept of these disorders falling along a spectrum rather than in neat little diagnostic boxes. 

“A more fundamental re-thinking of the nosological theory underlying the classification of psychiatric disorders will require the development of a conceptual framework that allows a better integration of clinical, neurobiological, genetic and behavioral data,” Jablensky wrote.

The DSM-5 and ICD-10 provide a helpful, pragmatic framework for clinical practice, but they remain collections of symptoms rather than a compilation of truly distinct disorders — perhaps also suggesting that the frequency of comorbidities points instead to multifaceted syndromes. Yet establishing definitions of disorders or spectra with validity, as opposed to just utility, is essential for continued understanding of genetic research.

“Our primary concern should be the progressive refinement of the utility of the diagnostic concepts and tools, towards the enhancement of their phenomenological accuracy, predictive value and capacity to guide person-focused treatment and management decisions,” Jablensky concluded.

Reference

Jablensky A. Psychiatric classifications: validity and utility. World Psychiatry. 2016;15:26-31.