Most cases were younger than respondents in controls. Majority of controls were Sidama in ethnicity; while, 54.1% (n = 20) of cases were in other ethnic groups. Proportion of being single was higher for cases than controls. Around 73% of cases were single, whereas only 38.8% of controls were single (Table–1.1). More than half of controls able to learn up to secondary school or above; however, majority of cases were illiterate or elementary school. Important differences in employment among cases and controls were also observed. For example, majority of cases were unemployed when compared to controls, see Table–1.1.
Correlates of Schizophrenia
[Insert Table 1.2 here]
In Table–1.2 majority of cases were younger than controls. This difference was genuine and statistical significant. Respondents with schizophrenia were found 2.6 times more likely to be younger than respondents without schizophrenia. Female respondents seam more likely to be affected by schizophrenia in this study; however, gender difference in the present study was not significant (OR = 1.89, p = 0.117).. Other evidences also showed the prevalence of schizophrenia across gender is similar2. Respondents with schizophrenia (cases) were also four times more likely to be single than respondents in controls (Table–1.2).
On the other hand, independent variables like educational background, ethnicity, and religion did not have an association to schizophrenia in this study, see Table–1.2. However, occupation and Catha edulis (khat) use were identified to be a risk factor for the outcome variable “schizophrenia”. Cases were 3.8 times more likely to be unemployed than controls and cases were almost 3.89 times more likely to use the leaves of Catha edulis (Khat) than controls,seeTable–1.2.
Discussion and Conclusions
According to the present study, schizophrenia was found to have significant association with respondents’ age, marriage, occupation and Catha edulis use. Majority of respondents with schizophrenia were younger than respondents without schizophrenia. Other evidences have supported these findings. Sadock et al2 and stated that schizophrenia starts at early age. Altamura et al8 also reported that schizophrenia occurs before the age of 40 years. Findings of the present study also confirmed that schizophrenia patients were more likely to be single and unemployed when compared to healthy controls. These findings were supported by different studies. Prasad13 reported that schizophrenia patients were less likely to be employed even when compared to people with other mental illness like bipolar affective disorders.
Significant association between Catha edulis (Khat) use and schizophrenia was also identified in the present study. Respondents with schizophrenia were almost four times at increased risk to use Catha edulis leaves (to chew Khat) compared to healthy controls. Results of the present study were in line with a case-control study done among Somalia refugees in Kenya20 and other few critical reviews21, in which these evidences had reported there was a causal association between excessive Catha edulis use and psychotic disorders. Odenwald et al18 also reported that the use of Catha edulis always precedes psychotic symptoms of cases with psychotic disorders. However, Zenebe et al22 had reported that there was no association between Catha edulis use and schizophrenia which is in contrary to the findings of the present study. This variation could be explained to the different designs used by researchers.
From the findings of the present study the researcher has concluded that age, marital status, occupation and Catha edulis (khat) use are independent predicting factors for schizophrenia.
This means that schizophrenia has early age of onset and economically productive age groups are highly affected by schizophrenia. Schizophrenia patients also spend long periods of their life without payable employment, getting marriage and on using substances like Khat (Catha edulis) that have a potential to worsen schizophrenia symptoms.
This study has tried to compare homogenous cases and controls by restricting their age to be between 18 to 50 years and selecting controls from close associates of schizophrenia patients. However, cases and controls were not matched for demographic variables in this study. All limitations for case-control study design are also true for this study.