Social Cognitive Theory variables as correlates of physical activity in fatigued persons with multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system (CNS) with an estimated prevalence of nearly 1 million adults in the U.S. (Wallin et al., 2019) The disease manifests as demyelination and transection of axons in the CNS, (Trapp & Nave, 2008, Bjartmar & Trapp, 2001) and, depending on the location of damage, results in a variety of symptoms. (Bjartmar & Trapp, 2001, Samkoff & Goodman, 2011, Dendrou et al., 2015) Fatigue is one of the most common, severe, and debilitating symptoms of MS, and it has effects on psychological, social, and behavioral outcomes.