A Retrospective Effectiveness Trial of Ketamine-Assisted Psychotherapy in Adult Patients Coping With Mental Health

Background: Ketamine-Assisted Psychotherapy (KAP) has shown positive effects within clinical trial settings and over short-term follow-ups, but sustained effects in real-world treatment settings remain unclear. In this study, we investigated the effectiveness of KAP in adult patients coping with mental health issues. We hypothesized that there would be significant reductions in psychological distress over time. Objective: To examine treatment effects at 1, 3, and 6 months relative to baseline on depression, anxiety, and post traumatic stress outcomes. Design: A retrospective intervention-only effectiveness trial. Setting: KAP was administered across 11 Field Trip Health clinics in North America. Intervention: KAP consisting of 4-6 guided ketamine sessions with psychotherapy-only visits after dose 1 and 2 and then after every 2 subsequent doses. Outcomes: Self-reported measures of symptoms of depression, anxiety, and post traumatic stress at 1, 3, and 6 months. Statistical Analysis: Analyses were by intention to treat. Main analysis was a mixed linear model or growth curve model to estimate change over time per outcome, yielding estimates of mean changes at each endpoint relative to baseline. Secondary analyses included evaluating case reductions (identified by cut-off values) and minimal clinically important differences (MCIDs) at each endpoint relative to baseline. Significance: This study may provide evidence of sustained real-world effects of Ketamine-Assisted Psychotherapy, of interest to patients, clinicians, researchers, and policymakers.