Age-adjusted threshold values for reduced REM latency in unipolar depression using ROC analysis.

To determine an age-adjusted, clinically meaningful depressive diathesis, we have implemented Receiver Operator Characteristic (ROC) analysis for mean rapid eye movement (REM) latency in patients with unipolar depression. Depressed patients were compared with age-matched normal control subjects. Sensitivity and specificity estimates were calculated for selected threshold values on the ROC curves as well as for the Research Diagnostic Criteria endogenous/nonendogenous subtype. The mean REM latency value of 65.0-66.0 min was most sensitive and specific for depressed patients aged 35-72. The threshold value of 70.0 min appeared optimally sensitive and specific for depressed patients aged 20-34. There was no effect of age on REM latency in the normal control sample. Among depressed patients there was an effect of age but this was clearly observable only in nonendogenous depressed patients.