Depression in Children with Inflammatory Bowel Disease
The incidence of irritable bowel disease has been increasing in recent years as obesity has increased. At a symposium at the 2014 meeting of the American Academy of Child and Adolescent Psychiatry, researcher Eva Szigethy discussed depression in inflammatory bowel disease, which most often involves Crohn’s disease or ulcerative colitis. These conditions are associated with increased levels of inflammatory markers such as interleukin 1 (IL-1), interleukin 6 (IL-6), and TNF alpha, and these in turn induce the acute phase reactive protein called c-reactive protein (CRP). The interleukins peak in the first 12 hours after an inflammatory challenge and CRP peaks at 48 hours and returns to normal at 120 hours. Il-6 is most closely associated with the somatic symptoms of inflammation, including depression, fatigue, loss of appetite, and decreased sleep, while TNF alpha is associated with non-somatic symptoms, such as irritability.
Szigethy found that in a randomized trial of cognitive behavior therapy versus supportive therapy in children with inflammatory bowel disease, inflammatory activity decreased significantly with cognitive behavioral therapy, and the therapy particularly helped the somatic symptoms of fatigue, sleep disorder, anhedonia (loss of interest in activities once enjoyed), appetite suppression, and mood dysregulation. In contrast, when antidepressants are given to those with inflammatory bowel disease, the drugs are not particularly helpful for these somatic symptoms. Inflammatory bowel diseases are treated with steroids in 21% of patients and with a genetically engineered drug called infliximab in 30%. Adding cognitive behavioral therapy to the regimen decreases CRP and red cell sedimentation rate, an associated measure of inflammation.
The discussant of the symposium on inflammation, Frank Lotrich, described how inflammation alters sleep, and this appeared to interact with genetic risk of illness. For example, those with certain genetic variations (the short SS allele of the serotonin transporter and the val-66-met allele of proBDNF) were most likely to experience sleep disturbance following treatment with interferon gamma, a treatment that fights the virus that causes Hepatitis C, creating inflammation in the process. Interferon gamma causes depression in about one-third of the patients who take it.
Lotrich pointed out that low levels of omega-3 fatty acids are associated with increased irritability and anger, and this is related to the presence of the A allele of TNF alpha. TNF alpha is also closely linked with irritability and anger, suggesting the possible benefits of omega-3 fatty acid supplementation to target irritability and anger more selectively. This would be consistent with the data of researcher Mary A. Fristad.
Il-6 is closely associated with the somatic symptoms of depression, particularly poor sleep, which is itself associated with increases in depression. This is consistent with inflammation being a marker of poor response to antidepressants; Lotrich noted that the selective serotonin reuptake inhibitors (SSRIs), which help depression, are far more effective against the non-somatic aspects of depression and less effective against low energy, decreased interest, and fatigue. However, extrapolating from the data on inflammatory bowel disease, cognitive behavioral therapy may be most helpful on these somatic symptoms.
