One-Year Outcomes Following Intravenous Ketamine Plus Digital Training Among Patients with Treatment-Resistant Depression

Introduction

Price and colleagues previously reported, in a randomised clinical trial, that a brief digital intervention based on Pavlovian conditioning—automated self-association training (ASAT)—appeared to prolong the antidepressant effect of a single ketamine infusion in patients with treatment-resistant depression. Those earlier results showed an effect on the primary clinician-rated depression outcome that persisted through the last in-person visit at 1 month postinfusion. Given that no waning was observed by the end of the acute-phase protocol, the investigators collected self-report data over a 1-year naturalistic follow-up to characterise the longer-term durability of the combined pharmacological and digital intervention. This paper reports a secondary analysis of that randomised trial, using the Quick Inventory for Depressive Symptoms, self-report version (QIDS-SR), to examine symptom trajectories across multiple scheduled follow-up time points up to 360 days after infusion. The aim was to determine whether the early synergistic benefit of ketamine plus ASAT persisted beyond the acute phase under naturalistic conditions and to identify when, if at all, group differences converged over the year-long follow-up.