OBJECTIVE: To determine the cost-effectiveness of fluoxetine and cognitive-behavioral therapy (CBT) for major depression in Thailand.

METHODS: A microsimulation model was developed to describe the variation in course of disease between individuals. Model inputs included Thai data on disease parameters and costs while impact measures were derived from a systematic review and meta-analysis of the international literature. Fluoxetine as the cheapest antidepressant drug in Thailand was analyzed for treatment of episodes plus a 6-month continuation phase and for maintenance treatment over 5 years of follow-up. CBT was analyzed for episodic treatment and for 5-year maintenance treatment. Results are presented as cost (Thai bahts) per disability-adjusted life-year (DALY) averted, compared with a "do-nothing" scenario.

RESULTS: The cost-effectiveness ratios of all interventions were below 1 time Thailand's gross domestic product of 110,000 bahts per capita. The uncertainty ranges around the cost-effectiveness ratios overlap: maintenance treatment with CBT 11,000 bahts per DALY (8,000-14,000); episodic treatment with CBT 23,000 bahts per DALY (10,000-36,000); episodic plus continuation drug treatment 33,000 bahts per DALY (26,000-44,000); maintenance drug treatment 38,000 bahts per DALY (30,000-48,000); and episodic drug treatment 42,000 bahts per DALY (32,000-57,000).

CONCLUSIONS: CBT and generic fluoxetine are cost-effective treatment options for both episodic and maintenance treatment of major depression in Thailand. Maintenance treatment has the greatest potential of health gain.