Research shows mental health struggles among those living with IBD are common. People with IBD are 2 to 3 times more likely to have depression and anxiety than the general population, the Crohn’s and Colitis Foundation reports. It’s easy to see how symptoms of IBD, including severe diarrhea, chronic pain, fatigue, and loss of appetite, could lead to social isolation and feelings of depression. But recent research suggests the relationship between the two conditions may be a bit more complex than that. A new study, published in April 2022 in the Journal of Gastroenterology and Hepatology, found a bidirectional link between IBD and depression (meaning people with one condition were more likely to develop the other). What’s more, this link extended to the siblings of people with either condition, suggesting a genetic component for the connection between these illnesses as well. “I think it’s important for people to understand that these conditions don’t happen in a vacuum, and there’s not just a single cause,” says Stephen Lupe, PsyD, a gastrointestinal psychologist and director of behavioral medicine in the department of gastroenterology, hepatology, and nutrition at Cleveland Clinic, who was not involved in the study. “We don’t know exactly what the mechanisms are but it’s some stew of environmental, genetic, and psychological factors.” In addition to these, Bing Zhang, MD, a gastroenterologist with Keck Medicine of USC in Los Angeles and author of the new study, says the gut microbiome — a community of trillions of bacteria and other microbes in the digestive tract — may also play an important role. The results showed that people with IBD were 9 times as likely to develop depression than the general population, while their siblings were nearly twice as likely to develop depression. When it came to people living with depression, those suffering from the mental illness were two times as likely to develop IBD, while their siblings without depression were one and a half times as likely to get the intestinal disease. For Dr. Zhang, the finding that people with IBD and their siblings were more likely to experience depression made sense. “IBD symptoms can be constant and very disruptive to a person’s life,” he says. “With siblings, there may be caregiver burnout or caregiver fatigue.” But the researchers were surprised to find that people with depression were prone to IBD. “This is the first study to find a bidirectional link between IBD and depression,” Zhang says.
Understanding the Gut-Brain
Zhang hypothesizes that the bidirectional relationship between IBD and depression has to do with the gut-brain axis. This is a scientifically established connection between the GI system and the nervous system, consisting of the brain and spinal cord. “The way I explain it to patients is to tell them to remember back when they were a kid and had a very big test, or even more recently if they had a big performance or job interview and all of a sudden, you have to go to the bathroom right before,” he says. “That’s a kind of a gut-brain response that everyone can relate to.” When it comes to IBD and depression specifically, Zhang speculates that inflammation of the brain, which plays a role in depression, may be connected to the inflammation of the gut, a distinctive feature of IBD. The gut microbiome may also play a role. In recent years, studies have linked changes in the gut microbiome to a number of different diseases. “We know that in patients with inflammatory bowel disease, there’s something called gut dysbiosis in which their microbiome is changed compared to their normal state,” he explains. “And this can also be found in patients with brain disorders, as well. So one of the things that we hypothesized was that maybe there were changes with the microbiome, which may actually stir up both things.”
Emphasis on Care of the Whole Person
The researchers say they hope their findings will encourage doctors to take into account both family history and the connection between gastrointestinal diseases and mood disorders when evaluating or treating patients with either IBD or depression. As a practicing gastroenterologist, Zhang always asks his patients about their mental health. “I always make sure to ask how they’re mentally coping with their GI symptoms, whether or not they’re feeling fatigued or stressed or depressed, and if they’re getting good sleep,” he says. Depending on their answers, patients may benefit from seeing a mental health professional. As a general rule, Dr. Lupe says if a person is thinking about seeking that extra support, it’s a good indicator that they should. “Definitely if they find themselves struggling, if they’re starting to not be able to engage in their life anymore, if there’s a lot of friction in their relationships, it may be helpful to get that outside perspective,” he says. Bringing in family members as part of the treatment plan can also be beneficial. Not only can family members provide support for the person with the disease, it can also be a way to screen loved ones for both depression and IBD. “I think it’s helpful to get an idea of what the situation is like at home and also to ask about things like caregiver fatigue and caregiver burnout,” Zhang says. “And since we know there’s a family component to IBD, if we’re talking to a sibling or first-degree relative, they might realize that they have symptoms, too. This might lead to earlier diagnosis so they can get better care.”
