Dr. Mark De Antonio, a clinical psychiatry professor at the Semel Institute for Neuroscience and Human Behavior at UCLA, died Dec. 31, after an extended illness. He was 67.

De Antonio, who joined the faculty at UCLA in 1988, also served as director of inpatient child and adolescent psychiatric service at the Resnick Neuropsychiatric Hospital at UCLA. He was known for his passion to provide care for severely mentally ill and vulnerable youth, especially those with developmental disabilities. During his career, he received numerous accolades and awards for his teaching and clinical expertise.

“De Antonio continued working up until two weeks before his death,” said Dr. Alexander Young, a professor and interim director of the Semel Institute. “A beloved teacher, master clinician, humanitarian, role model and colleague, he will be sorely missed.”

For many years, De Antonio supported the UCLA Pediatric HIV/AIDs program as a consultant and chaired a national child psychiatry committee on HIV issues. De Antonio also provided medical care to underserved children in Peru, where he made annual visits until interrupted by the COVID-19 pandemic.

A California native, De Antonio grew up in the San Fernando Valley. He graduated from UC Santa Cruz with a degree in molecular biology and received his M.D. from Stanford University School of Medicine in 1982. After three years in the general psychiatry residence program at Yale, he completed his training in child and adolescent psychiatry at the UCLA Neuropsychiatric Institute and Hospital.

Outside his professional career, De Antonio was proud of the accomplishments of his wife and two children. He also had a passion for music and film, the outdoors of the western United States, astronomy and animals. 

As news of his declining health circulated, former trainees and colleagues submitted nearly three hours of individual video testimonials. They expressed their gratitude for his impact on their careers as an educator and role model.