BACKGROUND: Considering the importance of depression and anxiety disorders in the new century and one of the important causes of disability and lost years worldwide and imposing a huge cost on the global economy, economic burden studies to determine the location of costs and the consumption of medical resources in recent years have contributed a lot to health policymaking. During the studies, it was found that the prevalence of these disorders increased significantly in Iran. This reason, along with the difference in the results of studies on the economic burden of depression and anxiety published in Iran in recent years, was one of the reasons for conducting a study of the economic burden related to these disorders in the East Azarbaijan province of Iran. METHOD: A retrospective, non-interventional, cross-sectional, social perspective study was conducted using a bottom-up approach for direct costs and a human capital approach for indirect costs. The data was collected from outpatients over the first four months of 2022 and from inpatients over the first nine months of the same year. Patients without age limits and suffering from at least one major depressive disorder (F32.0-F33.9), panic anxiety (F41.0), and generalized anxiety disorder (F41.1) and natives of East Azerbaijan province were included in the study. In the study for direct costs, the cost of measures that are paid directly in the process of diagnosis and treatment (medical and non-medical) were examined separately for outpatients and inpatients. For indirect costs, lost productivity due to absenteeism and premature death was calculated. For outpatients, a researcher's fee checklist form was made, and for the data of inpatients, the financial statement available in the medical file of the hospital's accounting system was used. Razi Tabriz and Imam Khomeini Benab hospitals and mental health centers of Tabriz were used as public centers, and specialist psychiatrists' offices of Tabriz were used as private centers. Patients with more than one comorbidity were excluded from the study. Total costs are reported at purchasing power parity rates. RESULTS: The data of 145 outpatients and 198 inpatients were analyzed to calculate the economic burden of MDD, Panic Anxiety, and GAD. The total economic burden for these disorders was obtained by 142.2 million purchasing power parity (ppp) dollars in 2022 for the East Azarbaijan province of Iran, with a population of more than 3.5 million people. The economic burden was divided into direct costs of 35.4 million dollars ppp and indirect costs of 106.79 million dollars ppp, representing 24.9% and 75.1%, respectively. The share of direct expenses of the outpatient group is 23.1% of this percentage, and the remaining 1.8% is for the inpatient group. In the case of indirect cost, from the percentage related to this sector, the share of lost productivity due to lost working days is 65.84%, and 9.26% is lost productivity due to premature death. For the outpatient group, the cost of medicine with 58.64% of the cost per person, and in the inpatient group, the cost of patient hoteling with 55.63%, and the visit of a psychiatrist with 20.34% of the direct cost per hospitalized person, the largest share of the direct costs of these people they assigned themselves. According to the method adopted in the study, the total cost showed the highest sensitivity to the GDP Per Capita (ppp) and the prevalence rate of anxiety and the prevalence rate of depression, respectively. CONCLUSION: Based on the results of the study, it is clear that indirect costs account for a significant share of the economic burden. Also, although the direct costs per inpatient are higher than the direct costs per outpatient, due to the difference in the number of outpatients and inpatients, the direct costs of the outpatient group have a larger share of the total cost of the disease. Considering the average age of patients and the large age gap to retirement age, health policymakers should take necessary measures to deal with and prevent the ever-increasing costs.