John Sweeney, PhD left us unexpectedly on September 10, 2023, at the age of 71, shortly after arriving in Chengdu, China, to enthusiastically fulfill his role as Visiting Professor at the West China Hospital of Sichuan University. Dr. Sweeney’s untimely departure marks the end of a brilliant career marked by unparalleled contributions to psychiatry and neuroscience and represents the loss of a luminary in neuroimaging and neuropsychopharmacology.

Born in Cincinnati, Ohio, John completed his undergraduate degree at the University of Cincinnati and Tel Aviv University and received his doctoral degree in clinical psychology from Syracuse University. He completed postgraduate training at the Payne Whitney Clinic at New York Hospital and Cornell University Medical College in New York. John’s academic journey took him to many places, both nationally and internationally. He was a member of the faculty at the University of Texas Southwestern Medical Center, the University of Pittsburgh, the University of Illinois, Bond University in Australia, and the University of Muenster in Germany. In 2016, he returned to University of Cincinnati where he was a Professor of Psychiatry and a highly regarded faculty member. Since 2015, John was an advisor and visiting professor at the Sichuan University in Chengdu, China, where he led an extensive collaboration of neuroimaging studies, until his last day.

Throughout his career, John made indelible marks on the scientific community. He was elected as a member of the American College of Neuropsychopharmacology in 2008 and went on to earn the distinction of becoming a Fellow and, eventually, a Fellow Emeritus in 2015. His advisory roles on several National Institutes of Mental Health scientific boards, editorial board memberships, and consultancy engagements with industry highlights his multifaceted expertise and influence within the field.

John’s scholarly legacy is nearly impossible to describe, with more than 1000 articles, reviews, and book chapters, including over 500 peer-reviewed articles. His research has been continuously supported by the National Institute of Health, with close to $75 M in funding. He was involved in more than a hundred studies. He was a true innovator, pioneering approaches ranging from EEG to fMRI, structural MRI to eye tracking, and an array of behavioral and neuropsychological measures. His research intentionally crossed the boundaries of psychiatric disorders, including autism, Fragile X, bipolar disorder, schizophrenia, and anxiety, while also focusing on understanding neurodevelopment across the entire spectrum of life.

A distinguishing hallmark of John’s work was his masterful ability to combine novel neuroimaging techniques, machine learning, genetics, treatment studies and clinical outcomes to advance our understanding of neurodevelopmental psychopathology. His had a profound talent for probing the neurofunctional features that underlie symptoms and often did so transdiagnostically. Beyond this, he brought clarity to the way in which we clinically approach psychiatric disorders and how we understand the complex ways in which symptoms overlap. In a field where the lines between disorders are often blurry, John’s work illuminated our understanding of specific symptoms and disorders and provided the context for clarifying neurophysiology. John had the unique ability to simultaneously see the big picture of a scientific problem and recite the intricate details of specific brain regions, subregions, or genes. When confronted with a complex problem or a finding that seemed counter to prevailing beliefs, he would wrestle with it and then fit this finding into understanding the illness, often offering a new perspective on how we see myriad neuropathologic processes. His vast knowledge and intellect were astonishing to all who had the good fortune to know him.

John was a role model for many for scientific passion and rigor. Many of his colleagues and mentees remember his extensive knowledge of the literature and painstaking, and always incisive revisions of their papers, penned by him often in the middle of the night. John was never shy about tackling inconvenient truths in his research (an example of this is his observation that atypical antipsychotics can cause cognitive impairment). He reveled in choosing complex topics, and identifying simple, elegant solutions for them. An example is his application of the well-known frontostriatal circuitry of eye movements to understand the complex neural circuitry disturbances in schizophrenia.

Although John was clearly an accomplished scientist, he was perhaps underrecognized for being a nurturing mentor who guided and inspired hundreds of individuals, from across the globe, throughout their careers. When mentoring, his skills as a clinical psychologist were often apparent, whether he was giving constructive feedback on specific aims of a grant application or eagerly providing guidance on addressing reviewers’ comments on a manuscript. His humility and generosity were evident by the fact that despite being the driving intellectual force behind many contributions, he would always let his mentees be the senior or first author of dozens of his high impact publications. With grace and humility, he could reconcile the perspective of a junior investigator, a collaborator’s conflicting interpretation, and an institution’s voice while helping all to understand and appreciate these differences. He deeply influenced the careers of many through his comforting wisdom and guidance.

In his spare time, John enjoyed traveling with his wife and spending time in their house at the lake. John’s gentle and affable nature, as well as his kindness and humor, all made him a cherished colleague, scientist, mentor, husband, family member, and friend. He is already deeply missed by all who knew him. John is survived by his wife, Marilynn, and his sister, Mary.