[Schizophrenic and bipolar endophenotypes: the clinician's point of view]

Abstract

Following empirical studies on schizophrenic and bipolar vulnerabilities, research on endophenotypes knows a recent major development. Two main definitions of early and stable vulnerability markers may be distinguished. First, a strict definition of endophenotype relies on a quantifiable and mainly paraclinical measure (e.g., biological data, electrophysiology or functional imaging). Second, a broader acceptance of the notion of stable and early markers may also involve clinical data. In this review, we first provide a short review on recent studies exploring two types of neurodevelopmental markers: neurological soft signs (NSS) and minor physical anomalies (MPAs). These two types of clinical signs feature robust, stable and heritable characteristics; however, a large heterogeneity of possible observed signs, and a limited clinical specificity may explain a relative reduced use in everyday clinical practice. Finally, psychopathology and subjectively experienced disturbances by patients may enable clinicians to better characterize specific, stable and heritable signs, constitutive of the schizophrenia spectrum disorders.