A study comparing pairs of identical twins has highlighted potential genes that may explain the common – but poorly understood – link between migraines and PTSD. The two conditions often co-occur, but researchers have historically known little about how or why.
The new study, published in Frontiers in Neuroscience, compared identical twins among whom one twin lives with PTSD or migraines, and the other does not. The team found common genes that may play a role in both conditions.
The researchers link the co-occurrence of PTSD and migraines to epigenetics – the process by which environmental factors or experiences can alter the expression of certain genes. Because identical twins have identical DNA, any genetic differences can be attributed to epigenetic factors caused by experiences and influences from the external world.
The team compared six sets of twins who had all experienced traumatic events – but only one in each pair had developed PTSD – to see which genetic changes co-existed in those suffering from PTSD.
They also enrolled fifteen pairs of twins within whom one in each pair suffered migraines, and similarly compared genetic changes occurring in migraine sufferers. By cross-comparing these changes, they were able to identify key genes implicated in the development of both conditions.
“Our results suggest that common genes and signalling pathways are involved in PTSD and migraine and this might explain why PTSD and migraine can co-occur frequently,” explains Divya Mehta of the Queensland University of Technology, senior author on the study. “This might further imply that common environmental risk factors for both PTSD and migraine might be acting on these genes.”
According to the Australian Institute of Health and Welfare, 12% of Australians will experience PTSD at some point in their lifetime, and around 20% of Aussies will experience migraines. This research may inform future therapies for both conditions, with the authors noting that epigenetic changes can be targeted and reversed using certain drugs.
“These results may have implications for treatments, as one medicine or therapy might only be effective for a single disorder,” said Mehta. “For co-occurring disorders such as PTSD and migraine, once we know which common genes are implicated in both disorders, we can develop new therapeutics to target these, thereby reducing symptoms and curing both.”
The authors note the small sample size as a necessary consequence of using identical twins with such particular sets of features.