PRIMARY BILIARY CHOLANGITIS (PBC) is a chronic inflammatory liver disease that leads to progressive bile duct destruction, often resulting in fibrosis, cirrhosis, and, in severe cases, liver transplantation. Affecting mainly women between their 40s and 60s, PBC is characterised by elevated liver enzymes, antimitochondrial antibodies, and symptoms such as pruritus, sicca, and fatigue.
Of these, fatigue is the most debilitating, reported by more than 40% of patients, and is often unrelated to disease severity. It significantly impairs daily life, contributing to psychological distress, anxiety, and depression. Despite ursodeoxycholic acid (UDCA) being effective in slowing disease progression, fatigue remains largely unaddressed.
The mechanisms underlying fatigue in PBC are still poorly understood, with biological, psychological, and behavioural factors all implicated. Evidence from other chronic diseases suggests that expectations and avoidance behaviours may play a key role in shaping symptom perception. To investigate this, researchers conducted an experimental study examining how verbal instructions, designed either to heighten or to reduce fatigue expectations, affected fatigue levels, motivation, and performance in people with PBC completing a demanding cognitive task.
Participants were divided into two groups: one receiving negative task instructions intended to induce fatigue expectations, and the other receiving positive instructions to reduce such expectations. Across both groups, fatigue and the urge to stop increased during the task. However, contrary to initial hypotheses, fatigue expectations did not differ between groups following instructions. Notably, participants given negative instructions reported a significantly higher urge to stop before beginning the task, indicating that verbal suggestions influenced motivation rather than subjective fatigue.
Further analysis confirmed that negative instructions increased the tendency towards disengagement throughout the task, without significantly altering perceived fatigue levels or task performance. These findings suggest that in PBC, motivational processes and fatigue, while closely linked, may operate partly independently. Verbal suggestions appear to shape willingness to persist with effortful activities, even when self-reported fatigue does not change.
This study highlights the potential of targeting expectations and motivational factors in behavioural interventions to manage fatigue in PBC. By addressing cognitive processes underlying disengagement, clinicians may help patients improve task persistence and overall quality of life.
Reference
Buck L et al. An experimental study on the effect of symptom expectations on mental fatigue and motivation in people with primary biliary cholangitis. Sci Rep. 2025;15(1):31464.
