Early response as predictor of final remission in elderly depressed patients.
BACKGROUND
Several studies have attempted to predict the final response or remission based on improvement during the early course of treatment of major depression. There is however a great variation in cut offs used to define early response and in the optimal week to predict final results.


OBJECTIVE
To compare different cut offs at different time points early in the treatment of elderly depressed patients.


METHOD
A 12 week randomised, controlled trial in 81 elderly inpatients with DSM-IV major depression comparing venlafaxine with nortriptyline. At least 20, 25, 30 or 50% improvement was analysed after 1, 3 and 5 weeks using the Hamilton Depression Rating Scale and the Montgomery Asberg Depression Rating Scale. We plotted sensitivity against 1-specificity and calculated areas under the curve (AUCs).


RESULTS
The highest percentage of correctly classified patients is found using at least 50% decrease as cut off in week 5, with acceptable sensitivity (81.8%) and specificity (87.4%). In week 5, the AUCs were 0.891 (95% CI 0.798-0.984) and 0.866 (95% CI 0.789-0.983) for the HAM-D and MADRS, respectively.


CONCLUSIONS
Combining the results from our study and the other studies addressing this issue, we suggest that the treatment should be changed in the elderly if after 3-4 weeks less than 30% improvement in depression score has been achieved.