To Örebro University

Background: Mental health (MH) has been reported to be poorer among patients with inflammatory bowel disease (IBD) than general population. However, it is not known whether MH is more driven by inflammation itself or related to gastrointestinal (GI) symptoms. Also, the dynamics of MH following IBD diagnosis is not well understood.

Methods: In the Swedish Inception Cohort of IBD (SIC-IBD), patients with Crohn’s disease (CD), ulcerative colitis (UC) and unclassified IBD (IBD-U) as well as symptomatic controls (SC) and healthy controls (HC) filled in Patient Health Questionnaire-9 (PHQ-9), a validated screening tool for depression. Patients completed PHQ-9 at diagnosis and at one year follow-up while the controls completed it once. Disease outcome was defined at one year based on requirement of advanced treatments/ surgery.

Results: In total, 286 individuals (16 HC, 89 SC, 62 CD, 104 UC, 15 IBD-U) completed the questionnaire at baseline. HC had significantly lower PHQ-9 score, (fewer depressive symptoms), at baseline compared to all the other groups (p<0.01). The baseline PHQ-9 score was not significantly different between SC and CD, UC and IBD-U patients (p=0.06).

At one year follow-up, 38 CD and 53 UC patients completed the PHQ-9. Between baseline and follow-up, UC patients had a significant drop in their PHQ-9 score (p<0.0000001), whereas CD patients did not have any significant change in their PHQ-9 score (p=0.06). Furthermore, UC patients had significantly lower PHQ-9 score compared with CD patients at follow-up (p=0.04, Figure 1).

Baseline PHQ-9 score was not correlated with calprotectin at baseline neither in UC nor CD patients (p=0.7 and 0.5 respectively). Also, there was no positive correlation between PHQ-9 score change and calprotectin change in either UC or CD patients, and neither baseline nor follow-up PHQ-9 scores were significantly different in patients with poor or good outcome (p>0.05). When analysed separately by sex, there was still no correlation between baseline PHQ-9 score and outcome in neither CD nor UC patients (p>0.05)

Conclusion: IBD patients have at the time of diagnosis more depressive symptoms than HC, but not different from SC. Depressive symptoms are more related to GI symptoms than IBD specific inflammation or disease outcome. UC patients show more of an improvement in their depressive symptoms one year after diagnosis than CD patients.