Dysfunctional self-reported interoception predicts residual symptom burden of fatigue in major depressive disorder: an observational study

BACKGROUND: Fatigue is a core symptom of major depressive disorder (MDD) and is frequently refractory to antidepressant treatment, leading to unfavorable clinical/psychosocial outcomes. Dysfunctional self-reported interoception (i.e., maladaptive focus on the body’s physiological condition) is prevalent in MDD and could contribute to residual symptom burden of fatigue. Therefore, we explored (a.) cross-sectional correlations between both dimensions and investigated (b.) prospective associations between interoceptive impairments at admission and symptom severity of fatigue at the end of hospitalization. METHODS: This observational, exploratory study included 87 patients suffering from MDD who completed self-rating scales, the Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), and the Multidimensional Fatigue Inventory (MFI-20), at the beginning and end of hospitalization. Bivariate correlations (r) and hierarchical regression analyses were performed. RESULTS: The cross-sectional analysis showed moderate to large negative correlations between the MAIA-2 and MFI-20 dimensions except for the Not-Distracting scale. Symptoms of general, physical, and mental fatigue at the end of hospitalization were predicted by reduced body Trusting (β = -.31, p = .01; β = -.28, p = .02; β = -.31, p = .00, respectively). Increased Body Listening (β = .37, p = .00), Not-Worrying (β = .26, p = .02), and diminished Attention Regulation (β = -.32, p = .01) predicted higher mental fatigue. CONCLUSIONS: Diminished body confidence at baseline identified patients at risk for post-treatment fatigue and could therefore serve as a target for improving antidepressant therapy. Body-centered, integrative approaches could address treatment-resistant fatigue in MDD. However, clinicians may also consider the potential adverse effect of increased Body Listening and Not-Worrying on mental fatigue in psychotherapeutic and counselling approaches. Due to the exploratory nature of this study, the results are preliminary and need to be replicated in pre-registered trials with larger sample sizes.