Estimating the effects of Mexico to U.S. migration on elevated depressive symptoms: evidence from pooled cross-national cohorts

Purpose: Migrating from Mexico to the U.S. is a major, stressful life event with potentially profound influences on mental health. However, estimating the health effects of migration is challenging because of differential selection into migration and time-varying confounder mediators of migration effects on health. Methods: We pooled data from the Mexican Health and Aging Study (N = 17,771) and Mexican-born U.S. Health and Retirement Study (N = 898) participants to evaluate the effects of migration to the U.S. (at any age and in models for migration in childhood or adulthood) on depressive symptom-count, measured with a modified Centers for Epidemiologic Studies-Depression scale. We modeled probability of migrating in each year of life from birth to either age at initial migration to the U.S. or enrollment and used these models to calculate inverse probability of migration weights. We applied the weights to covariate-adjusted negative binomial GEE models, estimating the ratio of average symptom-count associated with migration. Results: Mexico to U.S. migration was unrelated to depressive symptoms among men (ratio of average symptom-count= 0.98 [95% CI: 0.89, 1.08]) and women (ratio of average symptom-count = 1.00 [95% CI: 0.92, 1.09]). Results were similar for migration in childhood, early adulthood, or later adulthood. Conclusions: In this sample of older Mexican-born adults, migration to the U.S. was unrelated to depressive symptoms.