New research by University of Queensland scientists shows that people who have a higher genetic risk of depression are also more likely to have physical symptoms like chronic pain and fatigue. The October study was published in JAMA Psychiatry.
This meta-analysis, aimed at better understanding the biological background of depression, shows why looking at patients holistically, and assessing all their symptoms, including physical ones, is crucial for tackling depression.
The Relationship Between Genetics and Depression
“Genetics plays an important role in depression,” Enda Byrne, PhD, a researcher in psychiatric genetics at the University of Queensland and lead study author, tells Verywell.
Understanding which genes are specifically involved allows researchers to better understand who is at a higher genetic risk for depression.
“It was observed a long time ago that people who have a first-degree relative with depression are at increased risk of depression,” Byrne says. “But until recently, we knew little about which specific genes are involved.”
Recent research has identified more than 100 genetic variants associated with an increased risk of depression.
For this study, Byrne’s team conducted a meta-analysis and interpreted data collected by other studies. They pored over data from more than 15,000 participants, looking at detailed mental health history surveys, depression diagnosis, and saliva-retrieved DNA samples.
“Many patients with depression report physical symptoms such as aches and pains in the muscles and loss of energy, and a clinician assessing symptoms for clinical depression will ask about physical as well as psychological symptoms,” Byrne says. “Being that depression is quite a complex condition, the genetic risk factors may not all be the same for those experiencing physical symptoms and those who don’t.”
The researchers found that people with a higher genetic risk for clinical depression are also more likely to have chronic pain, fatigue, and migraine compared to people who don’t have such a high genetic risk. This can point to a vicious cycle. Physical symptoms like this can then also contribute to people’s mental health in a negative way.
“Depression is a complex condition and may be an umbrella term for a group of similar but distinct disorders,” Byrne says. “There is a wide range of symptoms reported by patients.”
Depression Hurts—Psychologically and Physically
It’s good to keep in mind that not all of the studies researchers looked at in this analysis used the same criteria to identify depression, Isaac Tourgeman, PhD, professor of neuropsychology at Albizu University, who was not involved in the research, notes.
While the study did show a significant relationship between depression and physical symptoms overall, it varied across the different studies that were reviewed, adds Tourgeman.
Still, these overall results are in line with most literature in the field.
“As the famous tagline from the antidepressant Cymbalta says, ‘Depression hurts,’” Tourgeman tells Verywell. “We often think of our bodies and minds being separate, but in reality, they are very much one.”
It would be very hard to experience pain or sadness without the brain that senses both, Tourgeman says. The relationship between physical symptoms and depression is biological, psychological, and cultural.
“For some [conditions] it’s a very linear process, meaning one gene variant equals a disease,” Tourgeman says. “For others like depression, it is much more complex with multiple gene variants being relevant and the interaction with the environment being vital.”
Genes are more like an outline or general plan while our experiences dictate the specifics, according to Tourgeman. For a condition like depression, situational factors, choices, and environment all play a role.
“Knowing our genetic make-up allows us to be more efficient and precise on how we go about our lives, and it’s very important when treating a patient," Tourgeman adds.
