People diagnosed with depression have a higher risk of Crohn’s disease and ulcerative colitis, but taking antidepressants may protect against the development of these inflammatory bowel diseases, a British study reports.
The study, “Depression increases the risk of inflammatory bowel disease, which may be mitigated by the use of antidepressants in the treatment of depression,” was published in the journal Gut.
Inflammatory bowel disease (IBD) encompasses a group of chronic inflammatory conditions of the gut, including Crohn’s disease and ulcerative colitis.
Inflammatory molecules of the immune system can also trigger depression, a mood disorder that is prevalent in patients with IBD. However, data on depression diagnosis, subsequent IBD development, and the effect of antidepressants is not conclusive.
Researchers re-analyzed data from patients with new-onset depression reported between 1986 and 2012 to evaluate the effect of the disorder and antidepressant therapy on the development of Crohn’s disease or ulcerative colitis.
A total of 403,665 patients (65% women) with incident depression were identified using The Health Improvement Network, which is a U.K.-based medical records database that provides anonymous primary care data for more than 12 million U.K. residents.
A control group of 5,323,986 individuals (50% women), without a history of depression, was also included in the study. The median age of patients with depression was 37 years, and control group participants were a median of 36 years old. The mean follow-up period was 6.7 years.
Medical records indicated that a significantly higher proportion of patients with depression (0.05%, or 203 patients) developed Crohn’s disease, compared with those in the control group (0.03% or 1,589 patients), the researchers found.
Similarly, a higher percentage of patients with depression (0.13%, or 539) were diagnosed with ulcerative colitis during the follow-up, compared with the control group (0.09% or 4,675).
Overall, for patients with depression, the risk of developing Crohn’s disease was 67% higher and ulcerative colitis 41% higher than those without depression.
To understand the relationship between depression and IBD independent of the factors that could govern depression, researchers adjusted the results for those factors, including age, sex, obesity, smoking status, socioeconomic status, anxiety, comorbidities (coexisting conditions), and antidepressant medications.
After this adjustment, the chances of a person with depression developing Crohn’s disease was 2.11 times higher and ulcerative colitis 2.23 times higher than those without depression.
Ulcerative colitis was less likely in patients with depression when treated with mirtazapine (66% less likely), serotonin-norepinephrine reuptake inhibitors (54%), selective serotonin reuptake inhibitors (SSRI; 52%), serotonin regulators (54%) and tricyclic antidepressants (TCA; 51%) compared with untreated patients.
SSRI and TCA treatment also had a similar protective effect on the development of Crohn’s disease, the study reported.
Researchers noted that smoking increased the risk of IBD development in this study population.
“Patients with a history of depression were more likely to be diagnosed with IBD. In contrast, antidepressant treatments were selectively protective for Crohn’s disease and UC. These results may impact counselling and management of depression and IBD,” the authors concluded.