Author information
1
Research and Development, VA Portland Health Care System, 3710 SW US Veteran's Hospital Road, Portland, OR, 97239, USA.
2
Department of Behavioral Neuroscience, School of Medicine, Oregon Health and Science University, Portland, OR, USA.
3
Department of Psychiatry, School of Medicine, Oregon Health and Science University, Portland, OR, USA.
4
Department of PM&R and Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
5
The Northwest Hepatitis C Resource Center, VA Portland Health Care System, 3710 SW US Veteran's Hospital Road, Portland, OR, 97239, USA.
6
Department of Gastroenterology, The Oregon Clinic, Portland, OR, USA.
7
Department of Neurology, School of Medicine, Oregon Health and Science University, Portland, OR, USA.
8
Department of Molecular Microbiology and Immunology, School of Medicine, Oregon Health and Science University, Portland, OR, USA.
9
Oregon Institute of Occupational Health Sciences, School of Medicine, Oregon Health and Science University, Portland, OR, USA.
10
Behavioral Health & Clinical Neurosciences Division, VA Portland Health Care System, 3710 SW US Veteran's Hospital Road, Portland, OR, 97239, USA.
11
Research and Development, VA Portland Health Care System, 3710 SW US Veteran's Hospital Road, Portland, OR, 97239, USA. marilyn.huckans@va.gov.
12
Department of Psychiatry, School of Medicine, Oregon Health and Science University, Portland, OR, USA. marilyn.huckans@va.gov.
13
The Northwest Hepatitis C Resource Center, VA Portland Health Care System, 3710 SW US Veteran's Hospital Road, Portland, OR, 97239, USA. marilyn.huckans@va.gov.
14
Behavioral Health & Clinical Neurosciences Division, VA Portland Health Care System, 3710 SW US Veteran's Hospital Road, Portland, OR, 97239, USA. marilyn.huckans@va.gov.
Abstract
Hepatitis C virus-infected (HCV+) adults evidence increased rates of psychiatric and cognitive difficulties. This is the first study to use functional magnetic resonance imaging (fMRI) to examine brain activation in untreated HCV+ adults. To determine whether, relative to non-infected controls (CTLs), HCV+ adults exhibit differences in brain activation during a delay discounting task (DDT), a measure of one's tendency to choose smaller immediate rewards over larger delayed rewards-one aspect of impulsivity. Twenty adults with HCV and 26 CTLs completed an fMRI protocol during the DDT. Mixed effects regression analyses of hard versus easy trials of the DDT showed that, compared with CTLs, the HCV+ group exhibited less activation in the left lateral occipital gyrus, precuneus, and superior frontal gyrus. There were also significant interactive effects for hard-easy contrasts in the bilateral medial frontal gyrus, left insula, left precuneus, left inferior parietal lobule, and right temporal occipital gyrus; the CTL group evidenced a positive relationship between impulsivity and activation, while the HCV+ group exhibited a negative relationship. Within the HCV+ group, those with high viral load chose immediate rewards more often than those with low viral load, regardless of choice difficulty; those with low viral load chose immediate rewards more often on hard choices relative to easy choices. Results show that HCV+ patients exhibit greater impulsive behavior when presented with difficult choices, and impulsivity is negatively related to activation in regions important for cognitive control. Thus, interventions that decrease impulsive choice may be warranted with some HCV+ patients.