Family and twin strategies as a head start in defining prodromes and endophenotypes for hypothetical early-interventions in schizophrenia

In an effort to share the experiences of 'genotype-hunters'-who have approa ched the difficult task of forecasting future schizophrenia in the young of fspring or other relatives of index cases, in new samples guided by the pri or probabilities of 15% in offspring or 50% in identical co-twins-with 'ear ly-interventionists'-who focus on purported prodromal symptoms in children who would be treated pharmacologically to prevent the development of schizo phrenia-we provide a focused review that emphasizes the hazards of false po sitives in both approaches. Despite the advantages prospective high-risk st rategies have had from clinical and laboratory findings that implicate some prodromal signs and endophenotypes, e.g. attention, memory, and informatio n processing evaluations, the yields are not sufficient for practical appli cations involving antipsychotic drugs for undiagnosed children. Even more c aution than usual is required, given the suggestions that the developing ne ocortex is vulnerable to dopaminergic exposure. (C) 2001 Elsevier Science B .V. All rights reserved.