While working in the ER, not long after Prozac came on the market in the late 1980s, she discovered the medication tremendously helped her depression. Later, when a doctor prescribed Lexapro, she found the results unsatisfactory, a conclusion explained by genetic testing. For more information on the role of genetics in drug response, check out Mastering Pharmacogenomics: A Nurse’s Handbook for Success, published by the Honor Society of Nursing, Sigma Theta Tau International.