Internet administration of the Edinburgh Depression Scale.

BACKGROUND Internet-based screening for depression is becoming increasingly important. The aim of this study is to validate the Edinburgh Depression Scale (EDS) for internet administration. METHODS In 407 participants (64% women; 36% men) with subthreshold depression (mean age=55 years; S.D.=4.9) positive predictive values for a syndromal CIDI diagnosis of clinical depression were calculated and compared to those from paper and pencil validation studies. At one-year follow-up, internal consistency and convergent validity of the internet-based EDS were determined in 177 participants by Cronbach's alpha and correlations with the internet-administered BDI and SCL-90 subscales depression and anxiety. RESULTS Positive predictive values ranged between 29% and 33% at cut-off scores of 12 to 14. Cronbach's alpha for the internet-administered EDS was 0.87. The EDS correlated significantly with the internet-administered BDI (r=.75; p<.001) and two internet-administered subscales of the SCL-90: depression (r=.77; p<.001) and anxiety (r=.72; p<.001). A major limitation is that the study was conducted without a control group of healthy subjects. CONCLUSION The psychometric properties of the internet-administered EDS are comparable to those of the paper and pencil EDS.