Background The influence of acculturation and nativity on depression in Latinos remains highly contested. One potential source of ambiguity is variation in their beliefs about the causes of their mental health ailments. Methods We conducted cross-sectional analyses of 450 older Latinos attending a rural mental health clinic near the U.S.-Mexico border. Primary diagnosis was grouped in one of 5 categories. The Center for Epidemiological Studies of Depression (CES-D) scale was used to measure depressive symptoms. Cultural variables included nativity and a validated acculturation scale. Patients rated their level of endorsement of 13 causes of mental health ailments A one-way ANOVA was conducted to identify cultural predictors of attribution items. Results Latinos had a mean age of 70.9 (SD = 9.1). The most common primary diagnoses were depressive disorders (67.1%) and dementia (15.3%). The mean CES-D score was 15.08 (SD = 18.16), but higher for the more acculturated (p = 0.048), and patients with psychotic (M = 26.31, SD = 19.78) and bipolar (M = 26.05, SD = 19.54) disorders. Acculturation increased attribution of mental health ailments to significant others (ρ = 0.091; p = 0.054), difficulty with work (ρ = 0.162; p = 0.001), and hereditary factors (r = 0.202, 95% CI = 0.002, 0.403). Patients with psychotic disorders were most likely to attribute their symptoms to curses (p = 0.001) and supernatural factors (p = 0.024) compared to other diagnostic categories. Conclusions Acculturated Latinos attriattribute their mental health ailments to life circumstances. This may intensify depressive symptoms and partly explains the relationship between acculturation and depressive symptoms. Further, the patients’ major diagnosis must be considered when evaluating acculturative influences on depression in psychiatric populations.