Based on the literature, the following three main aspects that form the basis for known and potential interactions between kynurenines (mainly KYNA) and the ECS will be discussed in the subsequent sections: (1) glutamatergic, dopaminergic, and GABAergic neurotransmission, given that KYNA and CB1R regulate all three; (2) astrocytes, given their significance in KYNA production and CB1R function; and finally (3) inflammation associated with schizophrenia, given that both the KP and ECS play important roles in this mechanism. Here, NPPA is linked to schizophrenia.