Prevalence and Associated Factors of Common Mental Disorders Among Adult Residents in Silte Zone, Southern Ethiopia

Introduction: Mental health problems appear to be increasing in importance in Africa. Mental and substance use disorders were the leading cause of yearly lived with disability in Sub-Saharan Africa. Evidence from previous studies shows considerable variation in the prevalence of these disorders. The most acceptable explanation for this wide variation is likely to be the fact that socio cultural factors are major determinants of mental disorders. Therefore a mental disorder has to be understood in a specific setting to develop effective and tailored interventions. Objective: The objective of this study was to determine the prevalence and associated factors of common mental disorders among adult residents in Silte Zone, southern Ethiopia Methods: Community based cross-sectional study was conducted in the study area. A total of 1178 adults were selected by using a three-stage systematic sampling technique. The Self-Reporting Questionnaire (SRQ-20) was used to determine the prevalence of common mental disorders. Data were analyzed by using SPSS version 20. Both bivariate and multiple logistic regression analyses were employed to identify factors associated with common mental disorders. Results: The prevalence of common mental disorders among adults found to be 39.7%. Increased age (OR = 1.114; 95% CI = 1.095, 1.134), being female (OR = 9.421; 95% CI = 5.947, 14.926), poor social support (OR = 1.987; 95% CI = 1.358, 2.907) and having life threatening experience (OR = 2.162; 95% CI = 1.825, 2.562) were significantly associated with common mental disorders. Conclusion: In the study, the magnitude of common mental disorders remains high in the study area. Increased age, being female, poor social support and having life-threatening experience were significantly associated with common mental disorders.


INTRODUCTION
Common mental disorders are a group of distress states manifesting with anxiety, depressive and unexplained somatic symptoms that typically come up in the community and prim-The global prevalence of common mental disorders from 1980-2013 was approximately 1 in 5 people experienced during the 12-month preceding assessment [4]. Adult mental disorders are found to be associated with high role impairment and economic burden [5,6]. According to the World Economic Forum, mental illness will account for more than half of the economic burden of disease over the next two decades -more than cancer, diabetes and chronic respiratory diseases combined. About 54% of the economic burden of disease falls to low-and middle-income countries [7]. Mental health problems appear to be increasing in importance in Africa. Mental and substance use disorders were the leading cause of YLDs (yearly lived with disability) in Sub-Saharan Africa [8].
Evidence from previous studies shows that mental disorders are common in all countries, there is a considerable variation in the prevalence of these disorders. In developed worlds, the past 12-month prevalence of mental disorders was found 14% in Greece [9] and 44% in a review of Bangladesh, India, and Pakistan [10]. In Africa, the past 12-month prevalence of common mental disorders was found between 10.3%-33.6% [11 -14]. This can be explained by deference in sociocultural factors across countries. Mental problems are influenced by social factors such as gender, social class, race and ethnicity, household patterns, poverty, violence, and other stressful social environments. They are not unique to any part of the globe [15,16].
Myths and misconceptions about mental illness contribute to the stigma, which leads many people to be ashamed and prevents them from seeking help. Generally, people who have mental disorders are considered lazy, unintelligent, worthless, stupid, unsafe to be with, violent, always in need of supervision, possessed by demons, recipients of divine punishment, unpredictable, unreliable, irresponsible, without conscious, incompetent to marry and raise children, unable to work, affect rich people, increasingly unwell throughout life, and in need of hospitalization [17].
Researchers found that Khat use is directly linked to common mental disorders [18]. Khat is a flowering plant that contains the alkaloid cathinone, which is said to cause excitement [19], which is common in Horne of Africa in including study area. According to the 2016 Ethiopia Demographic and Health Survey report, 12% of women and 27% of men reported the use of Khat [20]. The presence of khat in the study area may increase the burden of common mental disorders.
The majority of the global burden of mental disorders is located in low and middle-income countries [21]. Therefore, integration of mental health in primary health care in resourcelimited settings is more important for two reasons. The first reason is mental health resources are unlikely to be adequate to address the burden of mental disorders in low and middleincome countries. The second reason is most patients with mental disorders, particularly less severe disorders, prefer to seek care from their own family or primary health care settings [22]. Evidence from previous studies shows that mental disorders are common in all countries, there is a considerable variation in the prevalence of these disorders. Apart from methodological factors, the most acceptable explanation for this wide variation is likely to be the fact that socio-cultural factors are major determinants of mental disorders. Therefore a mental disorder has to be understood in a specific setting to develop effective and tailored interventions. Hence, this community-based study was intended to determine the prevalence and associated factors of common mental disorders among adult residents in the study area.

Study Design, Period and Area
Community-based cross-sectional study was conducted from January to April/2019 in Silte Zone. Silte zone is located 172km south of Addis Ababa, the capital of Ethiopia. The zone is divided into 10 Weredas (Districts) and 3 administrative towns. Wereda and administrative town are a cluster of kebeles which are the smallest unit administration. Ten Weredas (Districts) and 3 administrative towns consist of a total of 204 kebeles, and 211,012 households. According to the 2007 central statistical agency of Ethiopia, the estimated population size of the zone is 1,033,954, and 584,184 were adults.

Study Subjects
The source population of this study was all adults. Individuals whose age >=18 yrs and who have lived in the study area for at least 6 months were included. Individuals who had a hearing problem, cognitive and memory impairment were excluded.

Sample Size Determination
The sample size was determined by using single population proportion formula: with an assumption of prevalence rate of 33.6% (11) for common mental disorders from a previous study in Jimma southwest of Ethiopia, which gave the maximum sample size than prevalence rates found elsewhere in the country, margin of error(d) 4%, design effect of 2, Z=1.96 at 95% confidence level. Using the above information, the calculated sample size was 1071, and after adding a 10% potential non-response rate, the final sample size was 1179.

Sampling Technique
A three-stage sampling technique was employed for the study. The study unit was households with the assumption that each household would have a study subject. Using a simple random sampling technique, in the first stage, 4 Weredas were selected from the 13 Weredas of the zone. In the second stage, 36 kebeles were randomly selected out of 121 kebeles of four Weredas. The calculated sample size was proportionally allocated to selected kebeles based on the number of households found in the kebeles. In the third stage, 1179 households were selected by using a systematic random sampling technique. In the selected kebeles, there were 34187 households. When more than one study subject were found in one household, a lottery method was used to select a participant.

Measurements and Data Collection Tools
Twelve data collectors collected the data by using paper-based structured interviewer-administered questionnaire. The questionnaire was adapted from articles published in peerreviewed journals. A Self-reporting questionnaire  was used to classify whether a common mental disorder was present or not. Each of the 20 items scored 0 or 1. A score of 1 indicates the presence of symptoms, and 0 indicates the absence of symptoms during the last month. The maximum score is, therefore, 20. It has been validated in Ethiopia [23]. A score above the cut-off point indicates the existence of a probable mental disorder. In neighboring country Eritrea, a study found a good sensitivity and specificity at a lower cut of value (5/6) for SRQ-20 [24]. Therefore, in this study, 6 was used as a cut-off value to determine the presence or absence of CMDs. Another study in another part of Ethiopia also used 6 as a cut-off value for SRQ-20 [25]. The Oslo-3 Social Support Scale (OSS-3) was used to collect social support characteristics. The scale consists of three items. The sum score ranges from 3 to 14. By adding the three items, those with 3-8 values were considered to have poor social support, while those with 9-11 and 12-14 values were considered to have intermediate and strong social support, respectively [26]. OSS-3 has acceptable internal consistency and construct validity in the general population [27]. Finally, stressful life events were assessed by using an adapted version of the List of threatening experiences (LTE) questionnaire. It is a 12 items instrument measuring common life events that tend to be threatening [28].

Data Quality Management
Trained data collectors collected the data. A locally validated and translated tool was used to collect the data. The instrument was pretested in 5% of the sample size. It was conducted on individuals' study population who were not a part of the actual study. Based on the pretest results, the instrument was modified. Variables such as IV drug use, ethnicity, religion were modified in the final tool. The principal investigators and supervisors checked out the collected data for completeness, accuracy, consistency and clarity every day and made amendments before the next data collection measure. Principal investigators carefully cleaned and entered collected data into a computer.

Data Processing and Analysis
Data were checked for completeness and consistencies, then edited, coded and entered by using Epi-Info version 7 and exported to SPSS version 20. Both bivariate and multiple logistic regression analyses were employed to identify factors associated with CMDs. Then all variables significantly associated with bivariate analysis were a candidate to multivariable logistic regression analysis. Multivariable analysis was performed to see an association between dependent and independent variables. To estimate the strength of association, an adjusted odds ratio (AOR) with a 95% confidence interval was reported between study variables. A Pvalue less than 0.05 is considered statistically significant. Table 1 summarizes the socio-demographic characteristics of the study participants. Of the total 1179 initially planned for the study, 1168 participated in the study, with a response rate of 99%. The majority (63.7%) of the respondents were female. The majority of the participants were in the age group 45-54 years with a mean and standard deviation of 45±15 years. Most (91.8%) of the respondents were rural dwellers. Nearly twothird (74.7%) of study subjects had no formal education, and more than half (60%) of them were housewives. The average household size was 2±1.

Psycho-social and Lifestyle Factors
Among study participants, 530 (45.4%) reported no stressful life events, 463 (39.6%) reported one up to two stressful life events and the remaining 175 (15%) reported three and above stressful life events in the last four weeks. The majority (70.1%) of the participants had poor social support, 29.9% of the participants had intermediate social support and none of the study participants had strong social support. Out of the total 1168 study subjects, 876 (75%) never have a history of khat use, 235 (20%) reported the use of khat sometimes, and the rest 57 (5%) reported khat use usually. About 40% of the respondents had a family history of khat use. All of the respondents reported they are not current alcohol drinkers. Most (94.5%) of the respondents were non smokers.

Clinical Related Factors
About 582 (49.8%) of the respondents had a family history of mental illness, and 177 (15%) had a personal history of mental illness. Out of the total, 57 (4.9%) of the respondents had diabetes mellitus, 85 (7.5%) had hypertension and 68 (5.8%) had Asthma.

Prevalence of Common Mental Disorders
The prevalence of common mental disorders among adults was found to be 39.7% (N = 464/1168). When we look closely at the prevalence of specific symptoms of CMD (Table 2), the following symptoms were found to be highly prevalent: headaches (44.8%), uncomfortable feelings in the stomach (35.1%), easily tired (44.7%), sleep badly (29.8%) and feel nervous, tense or worried (29.6%), whereas symptoms like difficult of enjoying in daily activities (4.9%), difficult in decision making in day to day life (4.9%), unable to play a useful part in life (4.9%), lost interest in things (9.8%), feel that you are a worthless person (9.9%) and trouble thinking (10%) were relatively less common ( Table 2).

Factors Associated with Common Mental Disorders
Both bivariable and multivariable logistic regression analyses were done. Initially, all variables included in the study were analyzed using bivariable logistic regression. Then variables with p-value <0.25 were included in the multivariable analysis ( Table 3). In the bivariable model, increased age, being female, low educational status, poor social support and having a life-threatening experience were positively associated with CMD; and all these associations were statistically significant. In the multivariable model older age (OR = 1.114; 95% CI = 1.095, 1.134), being female (OR = 9.421; 95% CI = 5.947, 14.926), poor social support (OR = 1.987; 95% CI = 1.358, 2.907) and having a life-threatening experience (OR = 2.162; 95% CI = 1.825, 2.562) were significantly associated with CMDs ( Table 3).

DISCUSSION
The aim of this study was to assess the prevalence of common mental disorders and their associated factors. The results showed that 39.7% of the adults had common mental disorders. Our result is comparable with a study carried out in another area of Ethiopia and a review done in three countries of Europe (Bangladesh, India, and Pakistan), where it was estimated at 33.6% [11] and 44% [10], respectively. On the other hand, our finding is higher than those of two area studies of Ethiopia, namely in Harari 14.9% (25), a review in Ethiopia 21.58% [29]. Our finding is also higher compared to two studies conducted in Kenya, and a study in Greece reported 10.3% [13], 10.8% [12] and 14% [9], respectively. The variation might be due to distinctions in the measurement tools, and the socio-culture distinctions between Ethiopia and the other counties.
Regarding factors, we found a highly increased prevalence in women compared to men; CMDs were 9 times higher among female respondents compared to males. This finding is supported by other studies [11,30]. It may be attributed to gender-specific risk factors for common mental disorders that disproportionately affect women including gender-based violence, socioeconomic disadvantage, low income and income inequality, low or subordinate social status and rank and unremitting responsibility for the care of others [31] Older age is also positively associated with CMDs, older age increases the likelihood of CMDs. This result is consistent with that of previous studies done in Ethiopia and Kenya [11,25,32]. There may be multiple risk factors for mental health problems at any point in life. Older people may experience life stressors common to all people; stressors may be more common in later life, like a significant ongoing loss in capacities and a decline in functional ability lead to common mental disorders.
Adults who had poor social support were 2 times more likely to develop CMDs compared to those who had good social support. Evidence showed that the impact of social support on mental health can occur through two mechanisms: either as a main effect influence in which social support has a beneficial effect on mental health regardless of whether or not the individuals are under stress, or social support improves the wellbeing of those under stress by acting as a buffer or moderator of that stress [33].
In the current study, a strong association between stressful life events and common mental disorders was observed. Stressful life event increases the likelihood of having common mental disorders. This could be explained by hormones, neuroendocrine mediators, peptides, and neurotransmitters involved in the body's response to stress. Many disorders originate from severe and prolonged stress that leads to mental disorders [34,35]

Strengths and Limitations of the Study
The strengths of the study are the random sample of households, large sample size and the high response rate. Limitations of the study are the use of cross-sectional study design; we cannot permit conclusions about some variables, for example, about deciding whether common mental disorder symptoms are at risk or a consequence. The measurement used to diagnose common mental disorders was self-reported, which is subjected to recall and reporting bias. Further research should be conducted on risk factors for CMDs to strengthen and broaden our results.

CONCLUSION
In the study, the magnitude of the common mental disorder remains high in the study area. Older age, being female, increased family size, poor social support, and stressful life event were significantly associated with common mental disorders. Based on our findings, we would like to forward the following recommendation; mental health screening and counseling should be strengthened in health facilities; due attention should be given to the mental health aspect of those older adults, women, adults who have poor social support. Future research could beneficially include consideration of the severity and impairment of activities of daily living caused by CMD and would contribute to an understanding of the impact of CMDs on the lives of this population.

ETHICS APPROVAL AND CONSENT TO PARTI-CIPATE
Ethical clearance was obtained from Werabe University.

HUMAN AND ANIMAL RIGHTS
Not applicable.

CONSENT FOR PUBLICATION
Informed consent was taken from the participants.

STANDARDS OF REPORTING
STROBE guidelines and methodology were followed.

AVAILABILITY OF DATA AND MATERIALS
The data supporting the finding of the article is available in the Zenodo Repository at zenodo.org, reference number https://zenodo.org/record/5536246#.YVRi7JpBzIU and DOI is 10.5281/zenodo.5536246.

CONFLICT OF INTEREST
The authors declare no conflict of interest, financial or otherwise.

FUNDING
The study was funded by the Werabe University, and the funder was only involved by giving the funding for the design of a study, data collection, analysis, and interpretation.