Perceived stress four weeks after initiation of escitalopram monotherapy as a predictor of anxiolytic and antidepressant effects

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for depression and anxiety, yet response rates remain suboptimal. Clinically accessible predictors of treatment outcome are therefore needed to guide decision-making in routine care. METHODS: In this analysis, we examined data from a prospective hospital-based cohort of 92 outpatients with depression who initiated escitalopram monotherapy guided by therapeutic drug monitoring. The objective was to determine whether early levels of perceived stress predict subsequent treatment outcomes. Psychometric assessments included the clinician-rated Hamilton Depression (HAMD) and Anxiety (HAMA) Rating Scales and the self-rated Perceived Stress Scale (PSS), collected at baseline, week four, and week eight. Treatment outcomes were defined as absolute and relative changes in HAMD and HAMA scores at week eight, as well as response (≥50% HAMD reduction) and remission (HAMD 25), where remission was rare (1/21). The week-4 PSS score was also associated with improvement in anxiety symptoms, although less robust after adjustment for concurrent anxiety severity. CONCLUSION: Early perceived stress may represent a promising and accessible predictor of SSRI treatment outcomes. As an exploratory analysis, these findings should be considered hypothesis-generating and require replication before clinical implementation. The PSS is adaptable for digital platforms and may support future remote monitoring.