This study examined whether depressive symptoms increase with age longitudinally, and it evaluated two potential sources of influence-declining health and non-health-related negative life events. Adults aged 29-93 years from the Swedish Adoption/Twin Study of Aging completed the Center for Epidemiologic Studies-Depression scale three times at 3-year intervals. Analyses were performed on one twin (n = 877) and repeated on the second twin (n = 909) as a nonindependent replication. Depressive symptoms increased modestly with age in both men and women, particularly in the older participants. Health status was correlated with depressive symptoms, but new illnesses in the previous 3 years did not consistently predict increases in depressive symptoms longitudinally. Negative life events in the previous 3 years predicted depressive symptoms. Notably, depressive symptoms also predicted future negative life events.