Clinical characteristics of patients presenting with depressive states who are not receiving antidepressants: A multicenter observational study in Japanese psychiatric practice.

Abstract

Aim: To describe clinical characteristics associated with antidepressant non-use among patients presenting with depressive states in routine psychiatric practice and to explore factors associated with antidepressant prescription among patients with high diagnostic certainty for major depressive disorder (MDD).

Methods: This multicenter cross-sectional observational study used retrospectively collected routine clinical data from 35 psychiatric facilities in Japan. Eligible patients were those who attended participating facilities during March 2023 and were considered by their treating psychiatrist to be under clinical management for a depressive presentation or depressive episode at the index clinical assessment. All variables, including antidepressant use, current clinical state, symptom severity, and diagnostic certainty, were assessed at that single time point. At each site, when a patient not receiving antidepressants was identified, the next consecutively seen patient receiving antidepressants was enrolled as a comparator to facilitate contemporaneous between-group comparison. Physicians completed a standardized case report form including demographics, current clinical state, depressive symptom severity, and diagnostic certainty ratings for MDD and alternative diagnoses. Group comparisons were performed in the full cohort. Analyses restricted to patients with high diagnostic certainty for MDD were prespecified as exploratory, and a multivariable logistic regression model was fitted within this subgroup to examine factors associated with antidepressant prescription.

Results: A total of 1342 patients were enrolled (antidepressant use, n = 669; no antidepressant use, n = 673). High diagnostic certainty for MDD was less frequent in the no-antidepressant group than in the antidepressant group (22.1% vs. 38.5%). In the no-antidepressant group, commonly reported reasons for non-prescription included lack of diagnostic certainty (74.0%), clinical stability or absence of current symptoms (60.3%), and concerns about adverse effects (17.7%) (multiple responses allowed). In exploratory analyses restricted to patients with high diagnostic certainty for MDD (n = 400), remitted status and less severe symptom profiles were more frequent in the no-antidepressant group. In the multivariable model within this subgroup, severe or very severe symptoms (vs. no symptoms) were associated with higher odds of antidepressant prescription (odds ratio [OR] = 4.317, 95% CI 1.067-17.462, p = 4.0 × 10^-2), whereas age, sex, current state, and developmental disorder certainty were not statistically associated.

Conclusion: In this multicenter observational sample, antidepressant non-use among patients presenting with depressive states was associated with lower diagnostic certainty for MDD and with lower current symptom burden at the time of observation. Among patients with high diagnostic certainty for MDD, greater symptom severity was associated with antidepressant prescription. These findings may help contextualize conservative treatment decisions under diagnostic uncertainty in routine psychiatric practice.