A stronger linkage with CHRNA7 was obtained when the P50 auditorily evoked response deficits [89,90], an endophenotype of both schizophrenia and bipolar disorders, and nicotine, transiently normalized the P50 deficit in schizophrenic and bipolar disorder patients, thus confirming the involvement of a nicotinic receptor [91]. The gene discussed is CHRNA7; the disease is schizophrenia.