Intrinsic defects within blood vessels from the earliest developmental time points can directly contribute to psychiatric disease origin. Here, we show that nicotinamide adenine dinucleotide (NAD), administered during a critical window of prenatal development, in a mouse model with dysfunctional endothelial γ-aminobutyric acid type A (GABA) receptors ( endothelial cell knockout mice), results in a synergistic repair of impaired angiogenesis and normalization of brain development, thus preventing the acquisition of abnormal behavioral symptoms. The prenatal NAD treatment stimulated extensive cellular and molecular changes in endothelial cells and restored blood vessel formation, GABAergic neuronal development, and forebrain morphology by recruiting an alternate pathway for cellular repair, via previously unknown transcriptional mechanisms and purinergic receptor signaling. Our findings illustrate a novel and powerful role for NAD in sculpting prenatal brain development that has profound implications for rescuing brain blood flow in a permanent and irreversible manner, with long-lasting consequences for mental health outcome.