Table 1.
Characteristics of included studies (in chronological order).
| References | Country | Purpose | Number of patients with IBD (% males) | Age range or mean age (SD) where indicated; years | Presence of comparison groups and sample size |
|---|---|---|---|---|---|
| Huang et al. (2016) | USA (California) | Determine whether neural processing of somatic pain stimuli differs in adolescents and young adults with IBD and irritable bowel syndrome, as compared to healthy controls, and evaluate alexithymia, anxiety, depression, and pain catastrophizing. | 10 (50%) | 17–19 | Yes (10 patients with irritable bowel syndrome, 10 healthy controls) |
| La Barbera et al. (2017) | Italy | Investigate the association between IBD and psychological dimensions such as personality traits, defense mechanisms, and alexithymia. | 100 (51%) | Males: 40.7 (17.3); Females: 40 (14.1) | Yes (66 healthy controls) |
| Viganò et al. (2018) | Italy | Evaluate a broad spectrum of psychopathological symptoms and alexithymia levels in a group of outpatients affected by IBD in clinical remission, comparing CD and UC, and investigating the relationship with clinical and socio-demographic variables. | 170 (55.3%) | 47.10 (12.03) | No |
| Yanartaş et al. (2019) | Turkey | Investigate the effects of somatic and related symptoms, alexithymia, hypochondriasis, anxiety and depression on patients with major depressive disorder, irritable bowel syndrome, and IBD. | 54 (35.2%) | 36.46 (10.48) | Yes (102 patients with major depressive disorder, 51 patients with irritable bowel syndrome, 67 healthy controls) |
| Fournier et al. (2020) | France | Investigate whether difficulties in interoceptive abilities and difficulties in awareness of feelings are associated with the presence of irritable bowel syndrome, UC or CD, while checking for anxiety, depression, parasympathetic (vagus nerve) activity and cortisol levels. | 39 (46.2%) | UC: 40.9 (10.8); CD: 40.3 (11.2) | Yes (24 patients with irritable bowel syndrome, 26 healthy controls) |
SD, standard deviation; UC, ulcerative colitis; CD, Crohn's disease; IBD, inflammatory bowel disease.