Wernicke-Kleist-Leonhard phenotypes of endogenous psychoses: a review of their validity

While the ICD-DSM paradigm has been a major advance in clinical psychiatry, its usefulness for biological psychiatry is debated. By defining consensus-based disorders rather than empirically driven phenotypes, consensus classifications were not an implementation of the biomedical paradigm. In the field of endogenous psychoses, the Wernicke-Kleist-Leonhard (WKL) pathway has optimized the descriptions of 35 major phenotypes using common medical heuristics on lifelong diachronic observations. Regarding their construct validity, WKL phenotypes have good reliability and predictive and face validity. WKL phenotypes come with remarkable evidence for differential validity on age of onset, familiality, pregnancy complications, precipitating factors, and treatment response. Most impressive is the replicated separation of high- and low-familiality phenotypes. Created in the purest tradition of the biomedical paradigm, the WKL phenotypes deserve to be contrasted as credible alternatives with other approaches currently under discussion.

Concepts

This chapter offers a concise conceptualization of differentiated integration. It argues that differentiated integration can be understood as the differential validity of EU legal rules across the member states and is, thus, different from other forms of flexibility and non-compliance. Furthermore, the chapter introduces different modes of differentiated integration that have played an important role in the academic and policy debate: multi-speed, multi-tier, and multi-menu integration. Multi-speed differentiated integration is temporary. Multi-tier differentiated integration creates durable differences in the level of integration between groups of member states. Finally, in multi-menu differentiated integration, the composition of membership varies durably between integrated policy areas.