Studies on affective disorders in rural Ethiopia

Sammanfattning: Background Affective disorders are poorly defined and studied in sub-Saharan Africa despite their substantial public health impact. Objectives Overall objective: To describe the epidemiology of selected affective disorders in rural Ethiopia. Specific objectives 1. To describe the validity and utility of the concept of minor depressive disorder (mD). 2. To describe the manifestation, prevalence and the short-term clinical and functional course and outcome of bipolar disorder. Subjects and methods Population: Zay community residents (age ≥16), and residents of Butajira (ages 15-49), in Southern Ethiopia. Study design: Population-based cross-sectional and longitudinal studies Case identification: For the identification of cases with bipolar disorder, a two stage process was employed. An initial screen used key informants and interview with the Composite International Diagnostic Interview (CIDI) to identify cases with probable bipolar disorder. A second confirmatory diagnostic assessment stage employed the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). For the identification of cases with mD, data from the CIDI was used. Follow-up: 312 cases with bipolar disorder from Butajira were followed up for a mean of 2.5 years (ranging 1-4 years) through monthly clinical assessments and annual symptom and functional ratings. Results The CIDI was administered to 1714 adults among the Zay and to 68, 378 adults among the Butajira residents. The prevalence of mD among the Zay and Butajira was 20.5% and 2.2% respectively. Up to 80% of cases with mD had used services for their symptoms, while a third to a half of cases had thought about self harm. Up to a sixth of cases had attempted suicide. Age, marital status, education and somatic symptoms were independently associated with mD. The prevalence of bipolar disorder among the Zay was 1.8%. During a 2.5-year follow-up of 312 cases with bipolar disorder from Butajira, 65.9% relapsed (47.8% manic, 44.3% depressive and 7.7% mixed episodes) while 31.1% experienced persistent illness. Female gender predicted depressive relapse whereas male gender predicted manic relapse. Only being on psychotropic medication predicted remission (OR=3.42; 95% CI=1.82, 6.45). Disability was much worse among bipolar patients than in the general population and was predicted by symptom se3verity. Conclusions This is the largest study on mD and bipolar disorder in Africa. mD appears to have potential clinical utility in this setting given its association with service use and risk. The identified risk factors for mD also suggest potential aetiological continuity with major depression. The relatively high prevalence of bipolar disorder among the Zay may be related to genetic predisposition perhaps mediated through a founder effect, but other factors need exploring. In relation to the outcome of bipolar disorder, this study indicates that, contrary to previous assumptions, the course of bipolar disorder is characterised by both manic and depressive relapses in a relatively proportionate fashion. Bipolar disorder also leads to significant levels of disability. This is the only prospective outcome study of bipolar disorder in Africa where cases were monitored systematically at short assessment intervals. Therefore, findings are likely to be more robust than previous reports.