Minor psychiatric morbidity and internal migration in Brazil.

Studies of non-psychotic disorders in migrants have shown inconsistent results. This paper reports the findings of a case-control study carried out in three cities in Brazil to investigate the association between migration and minor psychiatric morbidity (MPM). Two hundred and seventy-six cases and 261 controls were selected from a survey of 6740 people aged 15 years or more. Diagnoses were made using the DSM-III Symptom Checklist. A statistically significant increase in risk of MPM in migrants was found by univariate analysis [odds ratio (OR) = 1.76; 95% confidence interval (CI) = 1.21-2.57. After controlling for gender, age, educational level, marital status, place of residence and position in the labour market, the overall increase in risk of MPM disappeared (OR = 1.02; 95% CI = 0.64-1.64), but a statistically significant increase in risk was present only in migrant unemployed women. This finding did not support models that explain risk in migrants by viewing migration as associated with cultural change and stressful life events. On the other hand, models based on the concept of selection- displacement from the labour market are more consistent with the present findings.