Brief self-rated screening for depression on the Internet

BackgroundThe Internet offers promising possibilities for the quick screening of depression for treatment and research purposes. This paper aims to validate three self-rated measures to screen for depression on the Internet: SID (single-item depression scale), CES-D (Center for Epidemiological Studies Depression scale) and K10 (Kessler psychological distress scale).MethodsOf the 502 subjects aged 18–80 who rated the SID, CES-D and K10 measures on the Internet, 157 (31%) subjects were also interviewed by telephone using the WHO Composite International Diagnostic Interview (C)IDI) for DSM-IV-disorders.ResultsCronbach's α for both web self-rated measures CES-D and K10 was 0.90. The SID correlated 0.68 (P < 0.001) with the CES-D and with the K10. The CES-D correlated 0.84 with the K10 (P < 0.001). Subjects with a DSM-IV diagnosis for any depressive disorder had significantly higher means (P < 0.001) on the three self-rated measures for depressive symptoms than subjects without a diagnosis of any depressive disorder. Using any depressive disorder as the gold standard, the area under the curve (AUC) of the SID was 0.71 (95% CI: 0.63–0.79), which was significantly lower than the AUC of the CES-D (AUC: 0.84; 95% CI: 0.77–0.90, P = 0.003) and of the K10 (AUC: 0.81; 95% CI: 0.73–0.88, P = 0.0024). The AUCs for the K10 and CES-D did not differ significantly from each other.LimitationsThe CIDI interviews were not recorded, so inter-rater reliability could not be calculated.ConclusionsThe CES-D and K10 are reliable, valid tools for care providers to quickly screen depressive patients on the Internet and for researchers to collect data.