In 1982, Paul and his colleague, Phil Skolnick, published their discovery that the ethyl ester of beta carboline-3-carboxylic acid (beta-CCE) triggered anxiety in people; the work was recognized as an example of the growing ability of neuroscientists to understand the biochemistry of emotions.
[3] In 1989, he was the senior scientist on a paper published in Nature that undercut the claim that mutations in a gene on chromosome 11 caused bipolar disorder, which previously had been hailed as evidence that studies of genetics would lead to definitive biomarkers for mental illnesses.
[8][9] As part of that effort he helped establish Lilly Chorus, an autonomous business unit that was created to design and execute studies that would allow drug candidates to "fail early" instead of lingering in a company's pipeline.
[10][11][12][13] He also led Lilly's work on Alzheimer's drugs, which however dramatically failed in Phase III clinical trials.
[14][15] Paul is also an adjunct professor of psychiatry and neurology at Washington University of St. Louis School of Medicine.