The speaker will review the December 10 article in the journal Nature summarizing DNA information from one million patients. Dr Nurnberger is one of the authors.
Dr Nurnberger is a retired IU School of Medicine faculty member and a previous speaker.
Program: The Genetic Relationships Among 14 Psychiatric Illnesses
Speaker: John Nurnberger, MD, PhD, Professor Emeritus – Neurobiology and more, IUSM and previous Scientech Club speaker
Introduced By: Marvin Miller
Attendance: NESC: 103, Zoom: 26
Guest(s): 2 in number but the editor failed to record names.
Scribe: Judy Weitzman
Editor: Carl Warner
Talk’s Zoom recording found at: https://www.scientechclubvideos.org/zoom/03302026.mp4
The speaker, John Nurnberger, Jr., MD, PhD, earned his BS in psychology from Fordham University, and then his MD and PhD from Indiana University. He completed his Residency in Psychiatry at Columbia Medical Center and served as a Medical Staff Fellow at NIH. In 1986, he returned to Indiana to head the Institute of Psychiatric Research at the IU School of Medicine until his retirement.
His work contributed to a major article in Nature magazine (“Mapping the Genetic Landscape Across Psychiatric Disorders,” December 10, 2025, https://www.nature.com/articles/s41586-025-09820-3).
Psychiatric disorders are normally diagnosed by clinical observation and subjective reports. These disorders are grouped by symptom similarity rather than genetic tests or biological markers. While there are no simple genetic markers that clearly identify psychiatric disorders, research has revealed familial clustering is associated with many of these. For example, barely 1% of the general population is likely to be diagnosed with bipolar disorder. However, that likelihood rises to 17% for individuals who have a relative with schizophrenia, and 80% for identical twins.
While there is a genetic influence, no single gene is responsible for these disorders and their odds. Bipolar disorder is a complex trait influenced by multiple genes and environmental factors. The genetic risk of being identified with a psychiatric disorder is primarily due to common variants with small effects supplemented by some rare high-impact variants.
Thanks to recent developments in RNA sequencing, and the shared work of multiple research groups with over one million subjects, we are now able to identify five different genetic factors common to 14 different disorders. The identification of these factors is not as simple as isolating the genes that determine such characteristics like eye color. Genetic traits associated with psychiatric disorders are extremely complex. Complex comparisons reveal similar behavioral outcomes from a range of genomes, family history, and some environmental factors.
There are a few important clinical applications of these findings. For example: * We can now test for certain enzymes to allow identification of effective anti-depressants for patients. * Genetic tests have markedly improved our ability to predict the likelihood of depression patients
eventually developing bipolar disorder. * Genetic screening can identify specific autism spectrum disorders, thereby informing therapeutic
strategies.
We are fortunate to be in a place where advances in genomics and transcriptomics, especially single-cell methods, provide new insights into disease biology at unprecedented resolution. With widespread collaborative science, the continued use of a large number of research subjects, and the inclusion of a more diverse pool of subjects, we anticipate highly refined and more positive identification and treatment of psychotic disorders.
John Nurnberger
