Single-cell technologies can identify transcriptional signatures in brains at the cellular level. In their Research Article “Single-cell multi-cohort dissection of the schizophrenia transcriptome” (24 May, p. 865), W. B. Ruzicka et al. use these technologies but primarily rely on tissues from older individuals, introducing agerelated confounds that could potentially distort conclusions about psychiatric disorders. Brain researchers should implement protocols to maximize access to brain samples from a variety of ages and disease stages.
