Karl Rickels, an emeritus professor of psychiatry in the Perelman School of Medicine, died on July 16. He was 100.

Born in Wilhelmshaven, Germany in 1924, Dr. Rickels was the son of Karl Eduard, CEO of a chocolate company, and Stephanie Roehrhoff, an elementary school teacher. He graduated from Abitur Berlin-Lichtenberg in 1942, then served briefly in the German Africa Corps during WWII, was captured, and became a prisoner of war in the U.S. for over two years. After returning to Germany in 1946, he enrolled in the University of Muenster, where he earned his MD in 1951. He moved to the U.S. in 1954, accepting a psychiatric residency at the Mental Health Institute in Cherokee, Iowa. A year later, he came to Penn to finish his psychiatry residency. He joined Penn’s faculty in 1957 as an associate professor of psychiatry. He became a full professor in 1969.

While at Penn, Dr. Rickels studied and developed outpatient drug therapy for individuals affected by anxiety, panic, and depressive disorders, becoming one of the first psychiatrists to study antianxiety and antidepressant medications in outpatients. Over time, his work expanded to include the treatment of premenstrual dysphoric disorder, and in 1977 he was named the Stuart and Emily Mudd Professor of Human Behavior and Reproduction. Dr. Rickels’s research was funded by the NIH’s National Institute of Mental Health continuously from 1959 to 2009 and contributed to the FDA approvals of the first and subsequent benzodiazepines (e.g. Librium, Valium, Ativan, Xanax), the anxiolytic Buspar, and several antidepressant SSRIs (e.g. Prozac) and SNRIs (e.g. Effexor). Dr. Rickels was the first physician scientist to demonstrate the efficacy of these antidepressants in the treatment of anxiety disorders.

Dr. Rickels’s contributions to medicine, which continue to be relevant today in the treatment of mental illness, earned him the National Institutes of Health Merit Award (1988), the Philadelphia Psychiatric Society Lifetime Achievement Award (2003), the University of Pennsylvania William Osler Patient-Oriented Research Award (2008), the International College of Neuro-Psychopharmacology Pioneer in Psychopharmacology Award (2012), and Penn Medicine’s Distinguished Graduate Award (2018). During his career at Penn, Dr. Rickels endowed three professorships in the department of psychiatry: the Karl Eduard Rickels Chair (1993), the Karl and Linda Rickels Chair (1999), and the Roehrhoff Rickels Chair (2015). Dr. Rickels authored more than 600 scientific publications, books, chapters, and reviews, including the 2011 autobiography A Serendipitous Life: From German POW to American Psychiatrist. He continued his research well into his 90s, retiring from Penn (and assuming emeritus status) in 2019.

“‘Opa,’ as Karl was affectionately known to his grandchildren and their friends, will long be remembered as an intrepid adventurer, partner in crime, dependable doughnut supplier, trusted confidant, and all-time favorite pal,” said the Rickels family. “Opa provided his loved ones and colleagues with the most priceless gifts: undivided attention, dedicated mentorship, and perpetual encouragement. Larger than life, Karl loved and was loved unreservedly. He will be greatly missed.”

Dr. Rickels is survived by his sons, Laurence, Stephen, and Michael; his daughters-in-law, Alyssa and Heidi; his grandchildren, Karl “Andrew,” Peter, Caroline, Claudia, Aiden, and Ashley; and his caregiver Marta Kubisiak.

In lieu of flowers, donations may be made to the Gladwyne Library League.