Gene Therapies May Provide New Dimension in Treating Post-Traumatic Stress Disorder (PTSD)
Eighteen specific, fixed positions on chromosomes (known as loci) associated with post-traumatic stress disorder (PTSD) are identified by researchers at the University of California San Diego, Veterans Affairs San Diego Healthcare System (VASDHS), Yale University, and West Haven VA, published in the journal Nature Genetics.
PTSD, long been known to be heritable, is a serious mental disorder that can occur after exposure to extreme, life-threatening stress, with a lifetime prevalence of approximately 7 per cent (but much higher among veterans). Traumatic events affect more than half to three-quarters of Americans over their lifetime, but most do not develop PTSD.
‘Role of multiple genes repeatedly implicated in diverse post-traumatic stress disorder (PTSD) phenotypes/symptoms is identified. This provides new insights into the fact that the genes were the key players in the development of the disorder. Hence targeting them for therapeutic drugs may provide better management of PTSD.’
Genome-wide association studies (GWAS) were conducted by the study team which analyzed the genomes of more than one-quarter - 250,000 persons of European and African ancestry participating in the Million Veteran Program, to determine the underlying mechanism of PTSD.
Genetic Link in PTSD
The symptoms of PTSD such as recurrent intrusive memories of traumatic events, severe emotional distress or physical reactions to reminders of traumatic events, self-destructive behaviors, and difficulty sleeping were surveyed from the Electronic health records of the veterans.
The relationships of PTSD to comorbid anxiety and depressive disorders were also explored. This may provide potential new targets for treatment. GWAS utilizes rapidly scanning markers across complete sets of DNA (the genetic material of a cell), or genomes, to deduct the genetic variations associated with a particular disease.
Despite the extremely diverse symptoms of PTSD, their genetic overlap is high. Hence to intrude more into their biology, a direct comparison of the heritability of diagnostic PTSD cases with continuous, symptom-based phenotypes of PTSD was done.
The study identified the role of multiple genes that were repeatedly implicated in different PTSD phenotypes. This indicates that the genes were key players in the development of the disorder and they might also be suitable targets for therapeutic drugs.
"These findings give us new insights into the biological basis of PTSD and point to some possible next steps for testing new treatments", says co-principal investigator Joel Gelernter, MD, professor of psychiatry, genetics, and neuroscience at Yale School of Medicine and VA Connecticut Healthcare System.
Facts on Post-Traumatic Stress Disorder (PTSD)
- Post-Traumatic Stress Disorder (PTSD) has an extremely complex phenotype, or set of observable characteristics, that is influenced by multiple genes
- Current diagnostic guidelines show up to 163,120 unique conformations of symptoms for the PTSD disorder
- The average age of occurrence of PTSD is 23 years
- There is a lifetime prevalence of 7.8% of an American experiencing PTSD with women twice as likely to develop it (10.4) as compared to men (5%)
- In a given year, 3.6% of American adults between ages 18 and 54 (5.2 million people) are affected by PTSD
Source: Medindia