CLOCK and schizophrenia: ► A mouse Snap-25 mutant shows abnormal circadian behavior reminiscent of schizophrenia ► The phase advance of activity is mirrored by SCN output and corticosterone release ► Importantly, the core molecular clock of the Snap-25 mutant is not affected ► We discuss a link between neurotransmission, circadian defects, and schizophrenia