Utilizing data from a clinical trial and an econometric model incorporating the impact of a medical intervention and regression to the mean, we present evidence supporting the hypotheses that for chronically depressed individuals: (i) the level of perceived at-work performance is negatively related to the severity of depressive status; and (ii) a reduction in depressive severity improves the patient's perceived work performance. Improvement in work performance is rapid, with about two-thirds of the change occurring already by week 4. Those patients having the greatest work improvement are those with both relatively low baseline work performance and the least severity of baseline depression.