The circadian nature of mood and its dysfunction in affective disorders is well recognized, but the underlying molecular mechanisms are still unclear. Here, we show that the circadian nuclear receptor REVERBa, which is associated with bipolar disorder, impacts midbrain dopamine production and mood related behavior in mice. Genetic deletion of the Rev-erba gene or pharmacological inhibition of REV-ERBa activity in the ventral midbrain induced mania-like behavior in association with a central hyperdopaminergic state. Also, REV-ERBa repressed tyrosine hydroxylase (TH) gene transcription via competition with nuclear receptor-related 1 protein (NURR1), another nuclear receptor crucial for dopaminergic neuronal function, thereby driving circadian TH expression through a target-dependent antagonistic mechanism. In conclusion, we identified a molecular connection between the circadian timing system and mood regulation, suggesting that REVERBa could be targeting in the treatment of circadian rhythm-related affective disorders.​