The diagnostic accuracy of late-life depression is influenced by subjective memory complaints and educational level in an older population in Southern Italy

•We estimated the accuracy of the 30 item-Geriatric Depression Scale (GDS-30) against the gold standard diagnosis of late-life depression performed with the Semi-Structured Clinical Diagnostic Interview for DSM-IV-TR Axis I Disorder.•In 843 older subjects from a large population-based study, at the optimal cut-off score (≥ 4), GDS-30 had 65.1% sensitivity and 68.4% specificity.•Using the standard cut-off score (≥ 10), the GDS-30 specificity reached 91.2%, while sensitivity dropped to 37.7%, with lower levels of screening accuracy.•The interaction between GDS-30 and educational level showed a significant effect, but not with age, gender, cognitive variables, apathy, somatic and psychiatric multimorbidity.•At the optimal cut-off score (≥ 7), the GDS-30 had better discrimination performances for the subjects with subjective memory complaints, with the educational level modulating diagnostic performance.