Ketamine Assisted Psychotherapy for Treating Comorbid Chronic Pain and PTSD

The goal of this pilot study is to evaluate the feasibility of conducting a clinical trial assessing if ketamine infusions combined to mindfulness therapy works better than psychotherapy alone to treat chronic pain and PTSD in adults living with both conditions. The objectives of the pilot study are to 1) assess the feasibility of the trial methods and 2) assess the feasibility and tolerability of ketamine treatment in combination with psychotherapy. The main questions the future full trial would aim to answer are: * Does the combination of ketamine infusion treatment and mindfulness therapy improve the quality of life in adults living with both chronic pain and PTSD more effectively than mindfulness therapy alone?" * Does the combination of ketamine infusion treatment and mindfulness therapy improve disability, and depressive, PTSD and pain symptoms in adults living with both chronic pain and PTSD more effectively than mindfulness therapy alone?" * Does implementing a brief ketamine infusion protocol safe and tolerable to treat chronic pain and PTSD? Researchers will compare ketamine infusion treatment combined with mindfulness therapy to mindfulness therapy alone to see if the combined treatment works better to treat chronic pain and PTSD. Participants will: * Attend 6 visits with a research team member to complete assessments and questionnaires. * Attend 4 ketamine treatment over 2 weeks, if allocated to the experimental group. * Attend 8 mindfulness therapy group sessions online (1 per week). * Log mindfulness exercises completed during the study period.