CFD and schizophrenia: Nest building has been proposed as a behavior with relevance to negative symptoms in schizophrenia.24 And we observed a gene-dosage-dependent nest-building impairment in the Df(h15q13)−/− and Df(h15q13)+/− mice.17 We also detected a decrease in acoustic startle response and prepulse inhibition in Df(h15q13)−/− mice, whereas Df(h15q13)+/− only had decreased acoustic startle response in accordance with previous characterization of the hemizygotes.9 Without direct tests of hearing, it cannot be ruled out that impaired hearing contribute to this phenotype in Df(h15q13)-/- mice.