Psychological Co-morbidity in Functional Gastrointestinal Disorders: Epidemiology, Mechanisms and Management

Abstract

Functional gastrointestinal disorder (FGID) is one of the commonest digestive diseases worldwide and leads to significant morbidity and burden on healthcare resource. The putative bio-psycho-social pathophysiological model for FGID underscores the importance of psychological distress in the pathogenesis of FGID. Concomitant psychological disorders, notably anxiety and depressive disorders, are strongly associated with FGID and these psychological co-morbidities correlate with severity of FGID symptoms. Early life adversity such as sexual and physical abuse is more commonly reported in patients with FGID. There is mounting evidence showing that psychological disorders are commonly associated with abnormal central processing of visceral noxious stimuli. The possible causal link between psychological disorders and FGID involves functional abnormalities in various components of the brain-gut axis, which include hypothalamic-pituitary-adrenal system, sympathetic and parasympathetic nervous system, serotonergic and endocannabinoid systems. Moreover, recent studies have also shown that psychological distress may alter the systemic and gut immunity, which is increasingly recognized as a pathophysiologic feature of FGID. Psychotropic agent, in particular antidepressant, and psychological intervention such as cognitive behavioral therapy and meditation have been reported to be effective for alleviation of gastrointestinal symptoms and quality of life in FGID patients. Further studies are needed to evaluate the impact of early detection and management of co-morbid psychological disorders on the long-term clinical outcome and disease course of FGID.

Hypothalamus-Pituitary-Adrenal Axis Hypersuppression Is Associated with Gastrointestinal Symptoms in Major Depression

“…For example, in IBS which exhibits a high degree of comorbidity with depression and anxiety disorders, 5,6 lowered secretion of ACTH and cortisol to a CRH challenge, lowered evening saliva cortisol and a lowered level of daytime ACTH secretion have been described. [9][10][11] Patients with functional somatic syndromes show negative correlations between morning saliva cortisol and depressive symptoms 48,49 and patients with major depression show a negative correlation between cortisol and somatoform dissociation.…”

“…4 Irritable bowel syndrome (IBS) patients also exhibit a high degree of comorbidity with depression and anxiety, possibly indicating shared mechanistic pathways connecting these disorders. 5,6 The underlying physiology linking GI symptoms and affective disorders is however poorly understood; dysfunction of noradrenergic pathways, serotonergic pathways, the autonomic nervous system, and the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as explanations. 5,7,8 The present study focuses on the HPA-axis, which plays a central role in the neuroendocrine response to stress with cortisol being it's main effector constituent, since both IBS and depression have been reported to exhibit HPAaxis dysregulation and that stress-dysregulation has been suggested as one important etiologic factor in both conditions.…”

“…5,6 The underlying physiology linking GI symptoms and affective disorders is however poorly understood; dysfunction of noradrenergic pathways, serotonergic pathways, the autonomic nervous system, and the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as explanations. 5,7,8 The present study focuses on the HPA-axis, which plays a central role in the neuroendocrine response to stress with cortisol being it's main effector constituent, since both IBS and depression have been reported to exhibit HPAaxis dysregulation and that stress-dysregulation has been suggested as one important etiologic factor in both conditions. [9][10][11][12][13][14][15][16][17][18] While stress has traditionally been associated with increased cortisol levels and HPA-axis hyperactivity, there is a growing body of literature describing lowered cortisol levels and hypoactivity of the HPA-axis in a number of stress related disorders [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] ; eg, posttraumatic stress disorder (PTSD), 30,31 chronic fatigue syndrome, [22][23][24] burnout, 25,26 as well as in fibromyalgia and chronic somatic pain conditions of unknown or uncertain etiology.…”

Brain-based Correlations Between Psychological Factors and Functional Dyspepsia

“…1 Aside from suffering cardinal dyspepsia symptoms, patients with FD usually experienced higher scores of psychological aspects and stressful situations. [2][3][4] For instance, anxiety and depression scores were often displayed above the normal range. 2,3 However, what role psychological factors play in symptom generation of FD patients has not been completely elucidated.…”

Commensal Bugs from the Gut-Shaping Human Health and Disease

“…Therefore, it is reasonable to include the gut microbiota as an important contributor to this system and as a result the term "microbiota-gut-brain axis" has come up [147,148]. Currently a growing number of clinical data and experimental observations suggest the presence of bidirectional gut-brain axis -implying that there are probably many types of neuro-atypical symptoms; including stress, depression, anxiety, associated with the alteration of the normal composition of gut microbial flora [149,150].…”