As the show begins, Paul is in his early 50s. Little is currently known about Paul's professional background or training, except that he obtained his BA and MS from Columbia and his PhD from The New School. However, in episode 27 season one, a Ph.D degree in Psychology from the University of Pennsylvania is visible in his office (he received post-doctoral psychoanalytic training at The New School in NYC). He also worked for a time at the fictional Baltimore Institute of Psychology under the tutelage of his mentor, Dr. Gina Toll.
Paul left the professional supervision of Gina nine years earlier after a large argument over reservations expressed by Gina in a letter of recommendation on Paul's behalf, among other issues. Since then, he has been conducting his practice from a home office, to the objections of his wife. Kate is frustrated by the fact that Paul always seems to be so "energetic" and "alive" in the office, but acts like an "anemic old man" outside of it. His suspicion that Kate is conducting an extramarital affair is confirmed when his wife tells him of it during a heated argument.
Furthermore, an extra tension is added when Laura, a 30-year-old patient, reveals her romantic feelings for Paul (addressed as "erotic transference") during one of their sessions together on Mondays. Realization of his own love for Laura slowly dawns on Paul when he begins to visit Gina for guidance on his problems both at home and work. In the end, Paul confesses to Laura his love for her at her home in the finale episode of Season 1, but a panic attack after receiving a call from his daughter, Rosie, stops him from consummating the relationship. Later, when a distraught Paul stops by Gina's house to tell her what happened, Gina concludes that Laura's decision to reject him after his anxiety attack means that through therapy, Paul has successfully made her realise that her attraction to him was merely a case of erotic transference. However, Paul appears to have been genuinely in love with her and was upset, saying that Laura may have been "the last love of my life, and I let her go."
In season 2, Paul is now divorced and has moved his practice to Brooklyn, New York. In the first episode of the season Paul is served with a malpractice lawsuit and becomes preoccupied with it.
Alex Sr. is suing Paul for negligence, charging him with failing to prevent the death of his son Alex, who voluntarily discontinued therapy and was killed in a plane crash that was either an accident or suicide. Alex Sr. and his lawyers contend that Paul's professional responsibility was to contact the military and report Alex Jr. unfit for duty. Alex Sr. later meets with Paul and makes a loaded offer: if Paul writes a letter taking blame for Alex Jr.'s death, he will drop the lawsuit, satisfied to have his belief that Paul is 100% at fault confirmed. Paul considers the offer but later concurs with Gina's advice and rejects it. The lawsuit is dismissed as frivolous, and Paul's angst about his professional competence is at least temporarily alleviated.