Due to the traditional popularity of B. monnieri as a brain tonic and the suggested use for Alzheimer’s disease (AD) [33], anxiety [34], depression [35] and epilepsy [36], mental disorder patients who are on prescription drugs might use B. monnieri as an alternative medicine, and some prescription drugs that are used for AD, anxiety, depression and epilepsy are metabolized by CYP2C19, CYP2C9, CYP1A2, and CYP3A4. The gene discussed is CYP2C9; the disease is major depressive disorder.