The Prevalence and Economic Burden of Treatment-Resistant Depression in Thailand

Background: The objectives of this study were to investigate the proportion of treatment-resistant depression (TRD) among patients with diagnosed major depressive disorder (MDD), to estimate the economic cost of MDD and TRD, and to examine the differences between MDD and TRD in a Thai public tertiary hospital. Methods This was a combined study between retrospective review of medical records and a cross-sectional survey. The sample size was 500 dyads of MDD patients and their unpaid caregivers. The concept of healthcare resource utilization, the Work Productivity and Activity Impairment Questionnaire: depression and mood & mental state versions (WPAI: D, MM), the Class Impairment Questionnaire (CIQ), and the Family Experiences Interview Schedule (FEIS) were applied as the tools of the study. Pearson Chi’s square, Fisher’s Exact test, and independent T-test were employed for statistical analysis. Results The proportion of TRD was 19.6% among MDD patients in a Thai tertiary public hospital. Age, age of onset of MDD, BMI, history of suicide attempt and self-harm, and frequent smoking behavior were significantly associated with TRD. The annualized economic cost of TRD was 276,059.97 baht per person ($7,668.33), which was significantly higher than this cost of non-TRD (173,487.04 baht or $4,819.08). The aggregated economic costs of MDD were 96.8 million baht annually ($2.69M) if calculated from 500 MDD patients and unpaid caregivers. This contributed to the economic cost of TRD 27.05 million baht (98 respondents) and the economic cost of non-TRD 69.74 million baht (402 respondents). Conclusions The economic cost of TRD was significantly higher than those of non-TRD, especially direct medical costs and indirect costs.