Background: Early adverse life events (EALs) and sex have been identified as vulnerability factors for the development of several stress-sensitive disorders, including irritable bowel syndrome (IBS). We aimed to identify disease and sex-based differences in resting state (RS) connectivity associated with EALs in individuals with IBS.
Method: A history of EALs before age 18 years was assessed using the early trauma inventory. RS functional magnetic resonance imaging was used to identify patterns of intrinsic brain oscillations in the form of RS networks in 168 people (58 people with IBS, 28 were female; 110 healthy controls, 72 were female). Partial least squares, a multivariate analysis technique, was used to identify disease and sex differences and possible correlations between EALs and functional connectivity in six identified RS networks.
Results: Associations between EALs and RS networks were observed. Although a history of EALs was associated with altered connectivity in the salience/executive control network to a similar extent in male and female patients with IBS (bootstrap ratio = 3.28–5.61; p = .046), male patients with IBS demonstrated additional EAL-related alterations in the cerebellar network (bootstrap ratio = 3.92–6.79; p = .022).
Conclusions: This cross sectional study identified correlations between RS networks and EALs in individuals with IBS. These results suggest that exposure to EALs before age 18 years can shape adult RS in both male and female patients in the salience/executive control network, a brain network that has been implicated in the pathophysiology of central pain amplification.
From the Oppenheimer Family Center for Neurobiology of Stress and Pain and Interoception Network (PAIN) (A.G., L.K., J.L., K.T., A.B., J.-Y.H., C.A.-M., B.N., E.A.M.), Los Angeles, California; Departments of Medicine (L.K., J.L., K.T., B.N., E.A.M.) and Psychiatry (J.L., K.T., B.N., E.A.M.) and Division of Digestive Diseases (A.G., L.K. J.L., K.T., B.N., E.A.M.), David Geffen School of Medicine at UCLA, Los Angeles, California; and Ahmanson-Lovelace Brain Mapping Center (E.A.M.), UCLA, Los Angeles, California.
Address correspondence and reprint requests to Emeran A. Mayer, MD, Oppenheimer Family Center for Neurobiology of Stress, 10833 Le Conte Ave, CHS 42-210, MC 737818, Los Angeles, CA 90095-7378. E-mail: email@example.com
Received for publication October 28, 2013; revision received April 13, 2014.