Psychomotor Slowing As a Predictor of Treatment Outcomes in Major Depressive Disorder with Acute Suicidality: Insights from the OASIS-D Study

Psychomotor slowing (PS) is common across mental disorders and has been linked to the clinical course of major depressive disorder (MDD). Prospective evidence as a predictor of treatment outcomes remains limited. We hypothesized that baseline PS severity would be associated with negative treatment outcomes in patients with MDD including the severity of acute suicidality. We analyzed data from a 6-month prospective, multicenter observational study of inpatients with MDD and acute suicidality. Depression (Montgomery-Asberg Depression Rating Scale), suicidality (Sheehan-Suicide Tracking Scale), Personal and Social Performance Scale (PSP), Work Productivity and Activity Impairment (WPAI, item #6) and quality of life (European Quality of Life Group, 5-Dimension) were assessed at baseline (T1), inpatient discharge (T2), and 3-months (T3) and 6-months (T4). Linear mixed models were fitted to examine associations between baseline PS (item #15 of the Quick Inventory of Depressive Symptomatology-Self-Report) and outcomes across timepoints, using Bonferroni correction. Among 235 participants (age = 36.4 ± 13.6 years; women = 57.9%), across all timepoints, baseline PS was significantly associated with greater depression symptom severity (p < 0.001), lower quality of life (p = 0.042), reduced leisure time productivity (p = 0.002), and higher suicidality (p = 0.001). The association of baseline PS with social functioning was negative (p = 0.043). Only for PSP, the association varied over time, i.e., T4 > T1 and T2 > T1. This first longitudinal study of PS in acutely suicidal MDD patients showed that baseline PS predicted a broad range of clinical and functional outcomes over six months. PS may serve as a prognostic marker and help identify distinct clinical trajectories in MDD.