Depressive symptoms in youth with inflammatory bowel disease compared with a community sample.

Crohn's disease and ulcerative colitis, collectively known as inflammatory bowel diseases (IBD), are chronic, immune-mediated diseases of the gastrointestinal tract. Incidence of IBD is increasing among youth in the United States; 25 to 30% of patients with IBD have onset of symptoms before the age of 18 years 1. IBD is characterized by unpredictable remissions of disease activity followed by relapses of symptoms including abdominal pain, diarrhea, rectal bleeding, weight loss, growth and pubertal delay, fever, fatigue, and arthritis 2. Managing IBD requires attention to complicated medication regimens, side effects, disease symptoms, and nutritional modifications or supplementation. In addition, youth with IBD require frequent medical appointments, and may be faced with recurrent school absences and needing to answer potentially embarrassing questions from friends and relatives 3. Youth with IBD have higher rates of school absences compared to healthy peers 1, 4, and up to 35% of patients experience permanent growth failure 5. They may appear younger than their chronological age, thereby increasing their risk of peer teasing or difficulty developing age-appropriate peer relationships. Given these challenges, the prevalence of emotional difficulties including depression among youth with IBD has been a topic of ongoing interest 6, 7. An accurate understanding of the prevalence and nature of mood disturbance in youth with IBD has important clinical and research implications. Decisions on how best to allocate clinical resources are guided based on perceived need, and documentation of base rates of depressive symptoms in youth with IBD is one indication of perceived need. Further, a better understanding of how youth with IBD compare to healthy youth on somatic symptoms of depression is needed to delineate the potential role of physical illness in elevating rates of depressive symptoms for those patients reporting difficulties. Youth with IBD reporting both higher levels of barriers to medication adherence as well as anxiety/depressive symptoms reported lower medication adherence, suggesting that the presence of depressive symptoms has important implications for disease management 8. Depressive symptoms have been of particular interest because of their potential association with steroid treatments and the inflammatory processes involved in IBD 9, 10. Findings regarding depressive symptoms in youth with IBD have been mixed, however. Mackner and Crandall 11 reported that, compared to parents of healthy adolescents, parents of adolescents with IBD rated their adolescents as experiencing greater difficulties with anxiety and/or depression on the Child Behavior Checklist, a standard questionnaire assessing global emotional and behavior functioning. Adolescents at least one-year post diagnosis, however, self-reported emotional functioning comparable to their healthy peers 12. An early study, limited by a small sample size of 20 youth with IBD, found higher rates of self-reported depressive and parent-reported internalizing symptoms for youth with IBD compared to a healthy control group 13. A recent meta-analytic review of psychosocial adjustment in youth with IBD differentiated the prevalence of depressive symptoms versus depressive disorders 6. A formal diagnosis of depression requires the presence of a sufficient number and chronicity of depressive symptoms and is typically derived via diagnostic clinical interview whereas depressive symptoms may exist in isolation of one another and are commonly measured via patient report on checklists or questionnaires. When measured using self-report on the Children's Depression Inventory 14, a standardized questionnaire assessing depressive symptoms, youth with IBD did not report elevations in symptoms when compared to both healthy youth and youth with other chronic illnesses. However, youth with IBD were found to experience higher rates of depressive disorders as measured via diagnostic interview when compared to youth with other chronic illnesses (odds ratio = 5.80) 6. A psychiatric diagnostic interview is considered the most reliable and valid methodology for diagnosing depression with highest sensitivity and specificity. However, in standard clinical practice, depressive symptoms are most commonly assessed via patient report, and the majority of the research on emotional functioning in patients with IBD is based on self or parent-report via questionnaires 6. There are mixed findings on the relationship between emotional functioning and IBD disease activity, suggesting that psychosocial factors need to be considered in addition to illness related factors when predicting emotional outcomes 15. Maternal depression, stressful life events, family dysfunction, and steroid usage have been shown to relate to higher rates of depressive symptoms 16, 17. Though not specific to youth with IBD, lower socioeconomic status is an additional risk factor for depressive symptoms 18. Given that youth with IBD are disproportionately from relatively advantaged backgrounds 19, 20 risk associated with lower SES may be less relevant for this population. Ambiguity in the literature on whether youth with IBD experience elevated rates of depressive symptoms and disorders has led to increasing interest in symptoms that could be accounted for by both physical illness and depression 10, 21. IBD is characterized by disease symptoms that overlap with somatic symptoms of depression including fatigue, changes in eating patterns, and sleep disturbance 11. Consequently, scores from self or parent proxy-reports of depression in youth with IBD may be conflating mood disturbance with disease symptoms and producing elevated rates of depressive symptoms for some patients that are at least partially due to disease activity. Recently, the factor structure of the Children's Depression Inventory was evaluated in adolescents with IBD, with results yielding a 3-factor structure of mood, behavioral/motivational, and somatic complaint symptoms 21. Items comprising the somatic complaints factor assess reduced appetite, tiredness, worry about aches and pains, and sleep problems. Interestingly, only the somatic complaint factor predicted IBD disease severity above and beyond current steroid dose, highlighting the overlap of somatic symptoms in physical illness and depressive symptomatology. Conversely, youth with IBD have been shown to experience lower levels of symptoms on the majority of items on the CDI, including somatic items, following cognitive-behavioral therapy for depression10. Decreases in somatic symptoms were independent of changes in disease severity for the most part, suggesting that somatic symptoms of depression may be responsive to psychological treatment regardless of disease activity. The first aim of the current study was to compare self-report of depressive symptoms by youth with IBD on the Children's Depression Inventory to a community sample from a similar geographic region with particular attention to somatic symptoms. The second aim was to examine the relationship between symptoms of depression and measures of disease activity. Interpretation of findings sought to (1) provide evidence of how youth with IBD compare to peers on symptoms of depression and (2) differentiate symptoms of mood disturbance from somatic symptoms potentially attributable to disease activity in order to gain a clearer understanding of how depressive symptoms are experienced by youth with IBD.