How Genes may Lead to Psychiatric Disorders
Digital illustration of DNA
Written by: Gabriel Fries, PhD
Psychiatric disorders are known to have a high heritability and a strong genetic component. This is evidenced by studies showing a high clustering of these disorders within families, in which first-degree relatives of patients have a significantly higher risk of developing behavioral alterations than the rest of the population. Unlike single gene diseases, in which the inheritance of a mutated gene from one or both parent(s) is enough to cause the disease in children, psychiatric disorders are complex. These disorders are caused by multiple genes interacting with each other and with a person’s lifetime experiences. This “genes by environment” interaction is normally required to trigger the onset of psychiatric disorders, making them harder to treat and predict from genetic testing.
How genes can interact with our life experiences is a question that scientists have been trying to understand for a long time. It is known that the presence of some genetic alterations can make a person more vulnerable or less resilient to the effects of some stressful situations. Two individuals experiencing similar traumatic events may develop different behavioral outcomes based on their distinct genetic makeup. More recently, the effects of environmental experiences in modulating epigenetic mechanisms have been proposed as mediators of these interactions. Epigenetic modifications can induce significant changes in our DNA without changing its sequence. These modifications have also been shown to be quite stable. For instance, epigenetic alterations induced during childhood after an early trauma may last until adulthood in specific cases.
Interestingly, several recent studies have reported epigenetic alterations in psychiatric patients. Researchers at the Translational Psychiatry Program, Psychiatric Genetic Program and the UTHealth Brain Collection for Research in Psychiatric Disorders are focused on better understanding the epigenetics of psychiatric disorders by studying blood samples from volunteers and post-mortem brain tissues of patients after consent from the next-of-kin. We hope that our studies will contribute to the identification of innovative biomarkers and clinically-relevant targets for the development of novel treatments.
Gabriel R. Fries, PhD, is a translational researcher in the field of biological psychiatry. His research focuses on the epigenetic basis of mood disorders, with a particular interest in bipolar disorder and molecular mechanisms of stress. His studies use basic science and investigation of cells, (epi)genomes and clinical datasets to better understand disease mechanisms and transmission, with the ultimate goal of designing novel medications and improving the lives of patients.