Dopamine β-hydroxylase (DBH) is a key enzyme in the catecholamine biosynthesis pathway, responsible for converting dopamine into norepinephrine. It is a member of the copper-dependent monooxygenase family, primarily localized in the vesicles of the adrenal medulla and neurons. DBH mediates crucial biological reactions and signaling pathways, such as stress response and emotion regulation, by hydroxylating the β-carbon atom of dopamine. Its gene expression is tissue-specific, particularly within the sympathetic nervous system and the brain. Changes in DBH activity or expression are associated with various neuropsychiatric disorders, including depression, schizophrenia, and hypertension. Genetic mutations can affect its enzymatic activity, thereby influencing the synthesis of norepinephrine.