A retrospective analysis of ketamine intravenous therapy for depression in real-world care settings

•Response to ketamine induction in the community is ∼ 50%; remission rate is 30%.•8% of patients worsen during ketamine induction for depression.•Ketamine induction reduces suicidal ideation in a majority of patients.•Durability of antidepressant response after ketamine induction is ∼ 60% at 8 weeks. Outcomes of ketamine intravenous therapy (KIT) for depression in real-world care settings have been minimally evaluated. We set out to quantify treatment response to KIT in a large sample of patients from community-based practices. We retrospectively analyzed 9016 depression patients who received KIT between 2016 and 2020 at one of 178 community practices across the United States. Depression symptoms were evaluated using the Patient Health Questionnaire-9 (PHQ-9). The induction phase of KIT was defined to be a series of 4–8 infusions administered over 7 to 28 days. Among the 537 patients who underwent induction and had sufficient data, 53.6% of patients showed a response (≥ 50% reduction in PHQ-9 score) at 14–31 days post-induction and 28.9% remitted (PHQ-9 score drop to