Prevalence and Impact of Treatment-Resistant Depression in Latin America: a Prospective, Observational Study

Abstract

Approximately one-third of patients with major depressive disorder (MDD) have treatment-resistant depression (TRD). The TRAL study will evaluate the prevalence and impact of TRD among patients with MDD in four Latin American countries. In this multicenter, prospective, observational study, patients with MDD were recruited from 33 reference sites in Mexico, Colombia, Brazil, and Argentina. Patients were assessed for TRD, defined as failure to respond to ≥ 2 antidepressant medications of adequate dose and duration. Demographics, previous/current treatments, depressive symptoms, functioning, healthcare resource utilization, and work impairment were also collected and evaluated using descriptive statistics, chi-square test, Fisher exact test, t-test for independent samples, or the Mann-Whitney nonparametric test, as appropriate. 1475 patients with MDD were included in the analysis (mean age, 45.6 years; 78% women); 89% were receiving relevant psychiatric treatment. 429 patients met criteria for TRD, and a numerically higher proportion of patients with TRD was present in public versus private sites of care (31% vs 27%). The mean Montgomery-Asberg Depression Rating Scale score was 25.0 among all MDD patients and was significantly higher for patients with TRD versus non-TRD (29.4 vs 23.3; P < 0.0001). Patients with TRD, versus those with non-TRD, were significantly more likely to be older, have a longer disease duration, have more comorbidities, be symptomatic, have a higher median number of psychiatric consultations, and report greater work impairment. Patients with TRD have a disproportionate burden of disease compared to those with non-TRD. Appropriate treatment for TRD is a substantial unmet need in Latin America. https://www.ClinicalTrials.gov identifier NCT03207282, 07/02/2017.

Keywords: Health care utilization; Latin America; Major depressive disorder; Prevalence; Treatment-resistant depressive disorder.

Fig. 1

Prevalence of TRD among patients with MDD, overall and by country. TRD treatment-resistant depression, MDD major depressive disorder, CI confidence interval

Fig. 2

MADRS scores for patients with MDD, non-TRD, and TRD. a Mean (SD) total MADRS score. b Distribution of MADRS scores by severity group. MADRS Montgomery-Asberg Depression Rating Scale, MDD major depressive disorder, TRD treatment-resistant depression, SD standard deviation