PSYCHIATRIC GENETICS - SEARCH FOR PHENOTYPES

Failure to obtain convincing results in psychiatric genetics can partl y be attributed to the fact that progress in molecular biology and gen etic epidemiology has not been followed by an equivalent development i n phenotypic description. Instead of relying entirely on classical nos ological approaches, we argue that identifying more homogeneous forms of diseases through a 'candidate symptom approach' among affected subj ects and an endophenotype approach that identifies sub-clinical traits among non-affected relatives might yield better results. Examples whe re these strategies have already been fruitful when applied to complex diseases are presented in this review. Focusing on vulnerability trai ts might stimulate the redefinition of traditional psychiatric syndrom es and help to bridge the gap between clinical and experimental approa ches.