BACKGROUND:Adherence to antidepressant treatment is demanded for both clinical and economic effectiveness in treated depression. The Lam Employment Absence and Productivity Scale (LEAPS) was acquired, re-validated and tested in blind randomization with Thai Depression Inventory (TDI). OBJECTIVES: To assess effects of antidepressant-based treatment among ambulatory Thai depressed patients after 3 months completed adherence to treatment with TDI and LEAPS.  METHODS: Thai depressed patients in public hospital under antidepressant-based treatment were follow-up, 50 were completed adherence for 3 months. The LEAPS and TDI were assessed independently by both psychiatrists and hospital pharmacist. Apparent economic impact of treatment was computed based on work-absence employed the minimum daily wage-average of workers of the region. RESULTS: CONCLUSIONS: Completed adherence antidepressant-based treatment is effective to reduce clinical symptoms of depression with reduction of work absence. The LEAPS and TDI are well correlated suggesting further evaluation for its benefits in larger depressed working population.