Fatigue and Its Longitudinal Associations With Mood, Stress, Anxiety, and Hair Cortisol During the Lockdowns of the Coronavirus Disease 2019 Pandemic: A Cohort Study With Ecological Momentary Assessment.

OBJECTIVE

Fatigue is a debilitating symptom common to many disorders and diseases (including COVID-19) with chronic fatigue affecting an estimated 10.1% of adults. However, fatigue in the general population remains understudied, especially during periods of crisis or sustained societal stress. We aimed to identify psychological and biological factors of fatigue during the COVID-19 lockdowns in the general population and to examine whether early fatigue predicted later fatigue, stress, anxiety, and mood.

METHODS

In this ecological momentary assessment study, 292 participants reported fatigue, stress, anxiety, and mood 5 times a day for two 7-day measurement periods (20,343 observations) during the 2 national lockdowns in Austria and Germany. Hair cortisol was obtained from 85 participants as a marker of long-term hypothalamic-pituitary-adrenal activity.

RESULTS

Fatigue was associated with younger age ( b = -0.27, p <.001), higher perceived stress over the past month ( b = 0.50, p <.001), higher loneliness ( b = 0.29, p <.001), and lower income ( p <.001). Lower hair cortisol levels were related to a steeper diurnal increase in fatigue during the first lockdown ( p = .014). Finally, higher fatigue during the first lockdown was related to higher fatigue, higher stress, higher anxiety, and worse mood during the second lockdown (all p < .001).

CONCLUSIONS

Factors associated with high fatigue during the lockdowns of the COVID-19 pandemic were young age, low socioeconomic status, higher perceived stress over the past month, and higher loneliness. Results further suggest hypocortisolism in fatigued individuals during COVID-19. Early fatigue may signal psychological vulnerability during large-scale stressors.