ACE and depressive disorder: Age was the strongest predictor, followed by female sex, population density, socioeconomic status, oral contraceptive use, gastroenterological complaints, obstructive airway medication, epilepsy, childbirth complications, smoking, angiotensin-converting enzyme (ACE) inhibitors use, antidiabetic medication use, upper airway symptoms and depressive disorder, heart disease, general psychiatric complaints, calcium channel blockers use, gastroprokinetic agent use, and influenza vaccination.