OBJECTIVES: To determine the economic impact of the use of the pharmacogenetic test obtained from a saliva sample, compared with standard care, in patients diagnosed with major depression in the Colombian context. METHODS: The model is a decision tree to simulate the natural history of the disease in two study arms; the use of a pharmacogenetic test in the treatment, according to the genetic profile, versus the standard care, evaluating the stabilization or non-stabilization of the symptoms in response to the treatment, based on the probabilities taken from the scientific evidence, and from real data took from a Colombian over a 12 month period. RESULTS: The total cost of treatment of a patient with major depression using the pharmacogenetic test and the standard care is USD $ 3,224.75 and USD $ 2,990.89, respectively. The difference of USD $ 233.86, is mainly associated with the cost of implementing the genetic test. However, the analysis showed that the costs of drugs have a reduction of 47% and a saving in the cost of hospitalizations of USD $ 793.14 in patients who undergo the genetic test compared to those following the standard care. In addition, the use of pharmacogenetics generates a saving of USD $ 496.56 in costs derived from disabilities compared with those following standard care. CONCLUSIONS: The use of pharmacogenetic testing in the treatment of patients with major depression generates savings in the cost of disability, in addition to reducing drug costs and hospitalization compared to standard care.