Discussion
In a national sample of Sierra Leoneans after more than a year of the unprecedented Ebola epidemic, nearly half of all respondents reported at least one symptom of anxiety or depression and three quarters expressed PTSD symptoms. Most respondents reported between one and four symptoms. After adjusting for sociodemographic variables, we found that persons with any level of Ebola experience were more likely to report symptoms of anxiety-depression and PTSD. Even though expression of one or more symptoms was widespread among our sample, a lower proportion of respondents met the clinical cut-off scores for anxiety-depression (5%–7%) and probable diagnosis for PTSD (15%–17%). The proportion of respondents who exhibited clinical level symptoms of anxiety-depression may be considered ‘lower than expected’ given the magnitude and duration of the epidemic, but may also point to a culture of resiliency among Sierra Leoneans.40 On the other hand, we documented substantial PTSD, which is a public health concern that may require targeted mental health interventions at the individual level and community level for those with some personal Ebola experience.
A national assessment of the mental health impact of the 2003 SARS epidemic in Taiwan, using a different scale than in our current study, found 4% prevalence of depression after the epidemic ended.3 Another population-based survey in Taiwan revealed 12% prevalence of psychiatric morbidity following SARS.9 In Singapore, a community-based sample detected that a quarter of all respondents had clinical levels of PTSD symptoms.11 Other mental health assessments with SARS survivors4 8 and HCWs5 documented similar or higher clinical PTSD levels compared with our current assessment. One study found that HCWs with a history of mental illness before SARS were more likely to report new onset following the epidemic.7 In our assessment, we cannot determine how past mental health history of PTSD in Sierra Leone, especially due to the prolonged civil war from 1992 to 2002, may have influenced the levels of clinical PTSD concern we detected.
Similar to SARS, the 2009 H1N1 pandemic was associated with psychological distress among the general population,13 14 20 family members of hospitalised patients with H1N121 and HCWs.18 In some instances, prevalence of H1N1-related anxiety was higher among those who had greater intolerance of uncertainty.15 17 Additional research is required to better understand the relationship between intolerance of uncertainty and quarantine experience during large-scale infectious disease outbreaks. An assessment with HCWs in China found that being quarantined and having perceived threat of SARS were associated with high depressive symptoms several years after the epidemic ended.10 In a separate study, H1N1 quarantine experience did not predict elevated PTSD levels while dissatisfaction with control measures was a better predictor.16
To the best of our knowledge, no prior study has assessed the mental health impact of the protracted Ebola epidemic at population levels in Sierra Leone, Liberia or Guinea. A limited number of studies have examined population-level mental health in other African countries. One such study in a predominantly rural community in Ethiopia found that 14% of the population expressed clinical levels of mild depressive, anxiety and somatic symptoms.41 On the other hand, a wide variety of studies have examined anxiety and depression in high-risk populations in Africa, including patients with tuberculosis in Ethiopia42 and Angola,43 Rwandans who had experienced genocide,44 and Nigerian prison inmates.45 Findings of varying levels of mental health symptomology from these studies suggest that further investigations may be required to better understand specific mental health impact of the Ebola epidemic on directly affected persons such as Ebola survivors.
In a systematic review, adverse mental health impact has been documented among conflict-affected persons.24 In Sierra Leone, during protracted civil conflict, exposure to traumatic events was associated with non-specific physical ailments.46 High prevalence of traumatic experiences and psychiatric sequelae has also been documented among Sierra Leonean refugees.25 Among war affected youth in Sierra Leone, social disorder and perceived stigma contributed to both externalising and internalising problems.47 Former child soldiers in Sierra Leone saw reliable improvement in PTSD symptoms over time, suggesting that a supportive environment may encourage resilience.48
A key recommendation in previous studies and WHO guidance is to integrate mental health into primary healthcare services.49 One study found global return on investments for scaling up treatment for depression and anxiety.50 An example of such effort is in progress in Sierra Leone wherein public health nurses are trained to screen patients for possible mental health needs.51 The WHO Mental Health Gap Action Programme emphasises that scaling up mental health services is a joint responsibility that requires collaboration from governments, health professionals, donors, civil society, communities and families.52
Limitations
Although a random national sample was obtained, our sample is not necessarily nationally representative. The sample had a higher proportion of respondents with any education compared with the general population.53 However, we did not find any association between education level and mental health symptoms, suggesting that this may not have influenced our findings. We acknowledge the necessity of validating survey instruments before using them in a new cultural context. Although PHQ-4 and IES-r have been widely used globally,31–37 54 neither has been validated nor used in Sierra Leone prior to this study. We therefore do not know the validity of clinical cut-off scores for our sample. To the best of our knowledge, PHQ-4 and IES-r (or the shortened form in this assessment) have not been used to measure population-level symptoms of mental health in any similar setting; making it impossible to compare our results to similar populations elsewhere. However, we found both had acceptable internal reliability and factorial validity. In the current survey, the PHQ-4 instrument demonstrated acceptable internal reliability (Cronbach’s α=0.78) and good factorial validity (GFI=0.999, CFI=0.999, RMSEA=0·030). The shortened IES-6 scale used in the present study demonstrated acceptable internal reliability (Cronbach’s α=0.78) and good factorial validity (GFI=0·998, CFI=0·998, RMSEA=0.023). In addition, the national sample was not designed to produce specific estimates for directly affected persons such as Ebola survivors, families of Ebola victims and quarantined persons. Moreover, there are no baseline/historical data available for comparisons. We also did not measure the effects of exposure to Sierra Leone’s civil conflict on long-term PTSD outcomes on the population prior to Ebola.