Depression as a mediator of chronic fatigue and post-traumatic stress symptoms in middle east respiratory syndrome survivors

Objective The relationship among chronic fatigue, depressive symptoms, and post-traumatic stress symptoms (PTSSs) among Middle East respiratory syndrome (MERS) survivors is poorly understood. Methods Of 148 survivors who consented to be registered and underwent assessments at 12 months (T1) and 18 months (T2) after the MERS outbreak, 72 (48.65%) were evaluated for chronic fatigue, depressive symptoms, and PTSSs based on the Impact of Event ScaleRevised (IES-R), the Patient Health Questionnaire-9 (PHQ-9), and the Fatigue Severity Scale (FSS). Data from 52 subjects, who completed both assessments, were analyzed using a regression-based serial multiple mediation model (PROCESS Model 6). Results Bootstrap analyses indicated no direct effects of T1 FSS on T2 IES-R but significant positive indirect effects of T1 FSS on T2 IESR through T1 PHQ-9 and T2 PHQ-9 (B=2.1601, SE=1.3268, 95% confidence interval=0.4250-6.1307). In other words, both T1 PHQ-9 and T2 PHQ-9 fully mediated the relationship between T1 FSS and T2 IES. Conclusion Chronic fatigue 12 months after MERS had indirect effects on prolonged PTSSs 18 months after MERS via persisting depression in MERS survivors. This finding supports the need to promote interventional programs for emerging infectious disease survivors with chronic fatigue to reduce depression and prevent prolonged PTSSs.