The PTSD Checklist for DSM-5 (PCL-5) will be used to assess PTSD symptoms (Weathers et al, 2013). This scale includes 20 items on a five point scale to assess for PTSD symptom severity. The total score ranges from 0 to 80 with higher scores indicate more severe symptoms.

Pain severity will be assessed with the pain severity subscale of the Brief Pain Inventory (Cleeland & Ryan, 1994). The subscale consists of four self-report items (rated 0 to 10), with a total score ranging from 0 to 40. Higher scores indicate higher pain severity.

Adherence to other medication treatments; 12-item self-report scale, scores range from 12-34, where lower scores indicate better adherence (adherence to medications not given as part of this study) (Kripalani et al. 2009)

The Five Facet Mindfulness Questionnaire (Baer et al, 2006) includes 39 self-report items assessing five dimensions of mindfulness. Items are rated on a 5 point scale ranging from 1 to 5, with total score ranging from 39 to 195. Higher scores indicate greater dispositional tendency to be mindful in daily life (e.g., observing, describing, acting with awareness, nonjudging of inner experience, nonreactivity to inner experiences).

The Difficulties in Emotion Regulation Scale-Short Form (Kaufman et al., 2016) includes 18 items that assess four areas of emotion regulation: awareness/understanding, acceptance, ability to engage in goal-directed behavior, ability to control impulsive behavior. The items are rated on a 1 (almost never) to 5 (almost always) scale based on frequency of feelings and use of emotion regulation skills, with a total score range of 18-90. Higher scores reflect greater impairments in emotion regulation skills.

The Executive Function Index has 27-item self-report inventory and assesses five facets of executive functioning (Spinella, 2005); Items rated "how well the following statement describes me" 1 (not at all) to 5 (very much), with a total score range of 27-135, with higher scores indicating higher levels of executive functioning.

The Savoring Beliefs Inventory (Bryant, 2003) is a 24-item self-report instrument with three subscales: anticipating, savoring the moment, and reminiscing. These items are rated on a 1 to 5 scale, half with a negative anchor and half with a positive anchor. Total scores can range from -72 to +72, with higher scores indicating higher levels of savoring.

The Positive and Negative Affect scales assess dispositional dimensions of affect (Watson, Clark, & Tellegen, 1998). Two separate subscales will be used. There are 10 items to evaluate positive affect and 10 items to evaluate negative affect with a range of 10-50 for each scale. Each item is rated according to frequency of feeling a certain way, with higher scores on each scale indicating higher positive or negative affect.

Self-report items will assess gender identity, race/ethnicity, family income, health insurance status, educational attainment, marital status, and employment status.

The Adverse Life Events Questionnaire is a 10 item self-report scale assesses adverse events in the first 18 years of life (Felitti, 1998). Total scores range from 0 to 10, with higher scores indicating greater number or adverse events.

The Life Events Checklist for DSM-5 includes 17 self-report items that assess a number of different types of traumatic events across the lifespan and personal occurrence versus learning about a traumatic event (Weathers et al., 2013). There is no formal scoring protocol, although endorsing 1 or more items indicates lifetime exposure to a traumatic event.

Current substance use disorders, major depressive disorder, and generalized anxiety disorder diagnoses will be assessed with the respective modules from the Structured Clinical Interview for DSM-5 (First, 2014). Each module includes structured interview questions in "yes/no" response format, with a scoring protocol that indicates whether the participant met criteria for the DSM-5 psychological disorder diagnosis. A categorical outcome will be used (scored "0" for did not meet criteria for the diagnosis, "1" for met criteria for the diagnosis).

The Adult Service Use Schedule includes 15 open-ended, self-report items assessing use of psychological services, accessibility, and length of service use (Bower et al., 2000).

Additional mindfulness practices engaged in outside of the study sessions assessed with four self-report items: 'Did you engage in mindfulness meditation in the past month?' (yes = 1, no = 0), 'How many days per week did you engage in mindfulness meditation?' (range = 0-7), 'How long in minutes did you meditate per session of mindfulness meditation?' (range = 0 to unspecified), 'Describe your practice of mindfulness meditation (what exercises/activities/techniques did you practice?). Each quantitative item will be analyzed separately as moderators of intervention outcome and reported descriptively.