Chunk #19 — DIMENSIONS OF PSYCHOPATHOLOGY IN NEUROLEPTIC-NAÏVE PATIENTS WITH RECENT-ONSET SCHIZOPHRENIA — Predictive validity of neurodevelopmental markers (MPAs and NSS) as a composite endophenotype of schizophrenia and its relationship with symptom dimensions
of MPAs predicted higher positive symptoms, negative symptoms, general psychopathology, as well as overall severity of psychopathology, whereas NSS did not show significant correlation with psychopathology indices. NRS and HS were most accurately classified (82.9%) when MPA and NSS were considered as a composite phenotype rather than independent. MPA and NSS thus constitute independent neurodevelopmental markers of schizophrenia and would afford greater predictive validity when used as a composite endophenotype in genetic association studies. This composite endophenotype could even be further refined by combining other neurobiological indices that are linked to these neurodevelopmental markers such as brain morphometry[4748] and neurocognitive deficits,[4950] thereby resulting in a much “cleaner” endophenotype for genetic studies. This approach involving refinement of the schizophrenia phenotype by including neurodevelopmental markers along with other endophenotypes that are closer to the primary effects of susceptibility genes than are clinical symptoms,[51] offers hope for tracking the multiple genes of small effect conferring vulnerability for the development of complex disorders such as schizophrenia.
