Differences in PHQ-9 Depression Severity between Adults Receiving Ketamine or Ketamine-Assisted Psychotherapy

Abstract

Treatment-resistant depression (TRD) affects roughly 2.8 million or 1.1% of the United States population. Many traditional treatments of mental disorders including various types of psychotherapy and pharmacotherapy do not provide adequate symptom reduction for clients, and many clients diagnosed with TRD seek out nontraditional treatments such as ketamine and psychedelics for their antidepressant effects. Due to the dissociative nature of psychedelic medication wherein resistance is reduced, and a trance-like state is induced, ketamine-assisted psychotherapy (KAP) has great potential as an adjunct to ketamine therapy. Procedures of KAP have been in development for the last 7 years and a consensus on protocol has been evolving. The purpose of this study was to determine the differences in depression self-report ratings using the PHQ-9 between clients who receive KAP versus clients who receive the infusions alone while controlling for baseline at intake and immediately following 6 infusions cycle. Common Factors conceptual framework was used to frame the study. Quade’s Rank ANCOVA was computed to determine that no significant differences exist in depression ratings between ketamine infusion only and KAP group, though paired samples t test results indicate statistically significant differences in depression ratings from baseline to follow-up in each treatment group. The positive social change implications are possible new treatment options for individuals who have been struggling with treatment-resistant mental health conditions, contribution to the literature on the effectiveness of KAP for TRD, and to help inform policy changes and establish needs for insurance coverage of ketamine and KAP.