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.

Inclusion criteria

• Written informed consent
• Over the age of 18
• Should be psychologically and medically cleared by a psychiatrist, family physician, or treatment team
• Diagnosed with Major Depressive Disorder (MDD), Bipolar Depression, Generalized Anxiety Disorder, Obsessive Compulsive Disorder (OCD), and Eating Disorder by a licensed healthcare practitioner (including Field Trip Consultants)
• A significant history of trauma and/or formal diagnosis of PTSD as per the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM 5)
• Individuals who have received Electroconvulsive Therapy (ECT) or other neuromodulatory treatments like Transcranial Magnetic Stimulation (TMS)
• Individuals reporting suicidal ideation may be included, as suicidal ideation is a symptom of a Major Depressive Episode (MDE)

Exclusion criteria

• Individuals who are unable to consent to the treatment
• Pregnant women and nursing mothers

--Note that Post Partum Depression (PPD) can be considered on a case-by-case basis in consultation with the National Medical Director.

• There is a relative (not absolute) contraindication for individuals with a Body Mass Index (BMI) of above 35. These clients must be given thorough consideration by the medical team.
• Any individual who has met DSM 5 criteria for a Substance Use Disorder in the past 3 months.

• Note that patients with alcohol, opioid, benzodiazepine, cocaine, and amphetamine use disorders need to go through detox (for alcohol/benzodiazepines) and be sober for 4 weeks.
• Note that mild active alcohol, cocaine, and cannabis use can be considered on a case-by-case basis at the comfort level of the treatment team if the client has demonstrated abstaining or significant reduction of use prior to starting treatment.
• Daily use of moderate to high doses of benzodiazepines
• Individuals who are experiencing psychotic symptoms as part of an MDE (mood congruent/ mood incongruent)
• Psychosis: Schizophrenia, Schizoaffective disorder, Bipolar 1 with psychotic features during mania
• Active Mania: Bipolar 1 (chronic non-disruptive hypomania is an exception at the discretion of the consultant)
• Borderline Personality Disorder
• Uncontrolled medical disorders
• Physical conditions with negative interaction with ketamine (e.g., metabolic blood disorder)
• Individuals with symptomatic acute brain injury within 90 days of serious injury
• Individuals diagnosed with moderate to severe sleep apnea
• Individuals who are unable to identify a person or service to assure their safe transport to home post treatment