The unpredictability of the chronic relapsing and remitting inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD), may impact psychological well-being profoundly. Whereas the exact mechanisms by which IBD is developed remains unclear, it is assumed that the disease develops due to an interaction of genetic predispositions, enviromental and dietary factors, gut microbiome and a dysregulated immune response (Lee & Chang, 2021).

Patients with IBD report a poor quality of life (QoL) and psychiatric complaints such as anxiety and depressive disorders (Bennebroek Evertsz’, Thijssens, et al., 2012). Moreover, a recent systematic review and meta-analysis demonstrated a high prevalence of symptoms of common mental health disorders in patients with IBD. According to validated screening instruments, one-third of IBD-patients are affected by symptoms of anxiety and a quarter by symptoms of depression in the previous 10-15 years (Barberio et al., 2021). Moreover, patients with active IBD were also found to have a higher probability of experiencing both anxiety and depression symptoms compared to patients with inactive IBD (Barberio et al., 2021). Although the causal pathway remains unclear, associations between depression, anxiety and disease activity are well demonstrated (Mikocka-Walus et al., 2016). Additionally, anxiety and depression were found to exacerbate disease outcomes in IBD patients (i.e. higher rates of surgery, hospitalization and corticosteroid use) (Keefer, 2021). Moreover, anxiety related irrational beliefs may lead IBD patients to disengage from regular restrictive physical activity (Gravina et al., 2023) and anxiety itself may reduce their therapeutic adherence, as was documented during the COVID pandemic (Pellegrino et al., 2022). Various studies point to a bidirectional link between the brain-gut axis (Gracie et al., 2018). This bidirectional link has been proven to affect the natural course of the disease along with mental health (Fairbrass et al., 2022; Peppas et al., 2021). Furthermore, individuals with a history of depression may show an increased risk of developing subsequent new-onset IBD (Piovani et al., 2024). A recent study found that IBD patients with anxiety and depressive symptoms have a higher risk of developing steroid resistance and IBD related poor outcomes (Duan et al., 2023). Additionally, two recent systematic reviews and meta-analyses (Naude et al., 2023; Seaton et al., 2024) have shown that psychological treatments, including CBT addressing mood disorders, also improve inflammatory biomarkers in IBD (i.e. faecal calprotectin and C-Reactive Protein). Consequently, an effective psychological intervention to target both anxiety and depression in IBD patients is important. Hence, we designed an ‘IBD-specific cognitive behavioral therapy (CBT)’ (Bennebroek Evertsz’, Bockting, et al., 2012), that targets anxiety, depression, Post Traumatic Stress Disorder (PTSD) and adjustment disorders for IBD patients with poor mental QoL. The beneficial effects were measured one month after ‘IBD-specific-CBT’ treatment as studied in a multi-center randomized control trial (QL!C study) (Bennebroek Evertsz’ et al., 2017). The QL!C-study consisted of an experimental group receiving immediate CBT (n = 59), and was compared with a wait-list control group receiving standard medical care followed by CBT (n = 59) (Bennebroek Evertsz’ et al., 2017). At baseline, (before starting the ‘IBD-specific-CBT’) we measured the prevalence of psychiatric disorders (SCID I), generic and disease specific QoL (SF-36, IBDQ), anxiety and depression (HADS, CES-D) in this IBD-patient group with poor mental QoL (Bennebroek Evertsz’ et al., 2017, 2020). We found a positive effect of ‘IBD-specific-CBT’ on disease specific QoL, generic QoL, depression and anxiety symptoms, one month after completion. Currently, the evidenced based ‘IBD-specific-CBT’ intervention for IBD patients has been implemented and disseminated in several hospitals in the Netherlands and showed comparable positive short–term effects on IBD-specific QoL, anxiety and depression (Bennebroek Evertsz’ et al., 2024).

Of the 57 (48%) IBD-patients who did not participate in this follow-up study (dropouts), 42 (74%) refused participation with no reason, 9 (16%) did not respond to letters and/or telephone calls, 2 (3%) persons indicated to be physically not able to participate and 4 (7%) persons were not able to participate due to time constraints. The dropout analyses (comparing baseline measures of the 61 patients participating at three-year follow-up vs the 57 dropouts) showed no significant differences regarding demographic and clinical characteristics and psychiatric disorders (DSM-IV) (data not shown). Dropouts had a significantly longer median disease duration of 11 years at time of baseline while participants who participated at follow-up’ had a ‘median’ disease duration of 5 years (p = .03).

The demographic- and clinical characteristics of 61 IBD-patients (response rate 52%) who completed the three year follow-up SCID-I telephonic interview assessment, are summarized in Table 1. Median age at long term follow-up was 36 years (IQR 28-47), 35 patients are female (57.4%) and almost more than two-fifth of our participants are married or living together (44.3%). Of the 61 participating IBD-patients there were 52 (85%) IBD-patients who also completed IBD-specific and generic QoL, anxiety and depression symptoms at three-year long-term follow-up. Median age was 35 years (IQR 28-47), 30 patients were female (57.7%) and nearly half of them were married or living together (43.4%) (see also Table 1). There were also no significant differences regarding demographic and clinical characteristics (and neither disease duration; p = .07) between the n = 52 participants who completed follow-up and patients lost to follow-up (data not shown). Assumptions of homogeneity of variances and normality of residuals were met for all multilevel analyses.

Multilevel regression analyses showed a significant decrease in estimated probability of overall psychiatric disorders (baseline 86.7% (n = 51), follow-up 38.3% (n = 24), p < .01), mood disorders (baseline 45.4% (n = 25), follow-up 20% (n = 13), p < .01), anxiety disorders (baseline 35.1% (n = 21), follow-up 10.7% (n = 8), p < .01) and adjustment disorders (baseline 30.6% (n = 23), follow-up 11.5% (n = 7), p < .01) (see Table 2). For the other psychiatric disorders, including eating disorder, alcohol related disorder and psychotic disorder, the number of participants with the disorder at baseline was very low (n < 5), precluding further analyses.

Additionaly, analyses showed a significant improvement in IBD-specific QoL between baseline and follow-up among 52 patients after three years (IBDQ total score: Cohen’s d = .89, IBDQ bowel: Cohen’s d = .69, IBDQ systemic: Cohen’s d = .79, IBDQ emotional: Cohen’s d = .79, IBDQ social: Cohen’s d = 73). Also there was a significant positive long-term effect on generic QoL (SF-36 physical: Cohen’s d = .54 and SF-36 mental: Cohen’s d = .69). Strikingly, patients showed significantly further improvement three years after completion of ‘IBD-specific-CBT’, concerning IBD-specific QoL total, IBDQ bowel, IBDQ social and generic physical QoL (completion versus follow-up IBDQ total score: Cohen’s d = .31; IBDQ bowel: Cohen’s d = .34, IBDQ social: Cohen’s d = .33, SF-36 physical: Cohen’s d = .32) (see Table 3).

Anxiety and depression symptoms remained decreased three years after completion of ‘IBD-specific-CBT’ (baseline versus follow-up HADS-A: p < .01, Cohen’s d = -.59; HADS-D: p < .01, Cohen’s d = -.41 and CES-D: p < .01, Cohen’s d = -.66). However, these results did not further significantly improve after completion of the therapy (completion versus follow-up HADS-A: p = .42, Cohen’s d = -.12; HADS-D: p = .67, Cohen’s d = -.06; CES-D: p = .20, Cohen’s d = -.19).

Ad hoc explorative analyses showed that there were some effects of disease-type (i.e., UC versus CD). Participants with CU showed a larger improvement between baseline and three year follow up on IBDQ total (p < .05), and the improvement between completion and three-year follow up for SF36-MH was only statistically significant for participants with CU (but not for participants with CD). There were no effects of age and gender. There were also no effects of gender, age and disease-type on the decrease of psychiatric disorders over time.

We found a sustainable positive effect up to 3 years follow-up of ‘IBD-specific-CBT’ on IBD-specific and generic QoL, anxiety- and depressive symptoms among IBD patients with a priori poor mental QoL. Moreover, comorbid psychiatric disorders at baseline had decreased at long-term follow-up three years after ending ‘IBD-specific-CBT’.

Recent meta-analyses and reviews did find short term effectiveness of CBT for IBD on mental health problems (such as anxiety and depression) (Chen et al., 2021; Li et al., 2019). However, to date, positive sustainable effects of ‘IBD-specific-CBT’ have not been demonstrated.

After 24 months of observation, Mikocka-Walus et al. (2017) did not find a significant longterm effect of CBT on QoL, mental health or coping. A study of McCombie et al. (2016), that examined the long-term effect of computerized CBT, found an increased QoL at 12 weeks but the effect was not maintained after 6 months. In patients with other medical illnesses, little is known about the sustainable effects on mental symptomatology and mental condition as well as QoL after CBT (van Straten et al., 2010). However, sustainable effects of CBT have been reported for depressive disorder (Cuijpers et al., 2013, 2023; Furukawa et al., 2021; Legemaat et al., 2023).

We would recommend a number of amendments for future research to investigate the sustainable effects of ‘IBD specific CBT’. First, employment of a larger sample size that would accommodate dropout, enabling the study of long-term effects. Furthermore, inclusion of multiple assessment points (e.g., 3, 6 and 12 months after completion) would enable a closer examination of the treatment effects over time. Even more so, in the first phase of this study we randomized CBT to a wait-list control group. Therefore we have no control group for the three year follow-up. We would recommend to use a different type of control-group. Namely comparison of ‘IBD-specific-CBT’ with IBD patients receiving only treatment as usual for longterm follow-ups. Fortunately, this research will be repeated with due observance of these recommendations.

Given these promising short-term and long-term results of ‘IBD-specific-CBT’ in IBD patients with poor mental QoL and the positive results of the aforementioned implementation study of ‘IBD-specific-CBT’ in four hospitals in the Netherlands (Bennebroek Evertsz’ et al., 2024), there is an urgent need to disseminate standard stepwise screening and treatment of mental health disorders in IBD patients. As mentioned before CBT for patients living with IBD not only enhances psychological benefit, but may also improve their physical health (e.g. inflammation) (Naude et al., 2023; Seaton et al., 2024).

Moreover, providing integrated psychological care to IBD patients in need for mental health can reduce costs, particularly by decreasing visits to emergency departments (Lores et al., 2021). However, untill now the integration of mental health care in general IBD care is still insufficient and a challenge in daily clinical practice (Fairbrass & Gracie, 2021; Peppas et al., 2021).