This is a 12-week online mindfulness-based course blended with therapist support via video link using shorter, more frequent practice than standard Mindfulness-Based Cognitive Therapy (2x15-minutes/day).

The FFMQ-15 is a questionnaire to assess levels of mindfulness in daily life. It assesses five aspects (or facets) of mindfulness: observation (noticing our internal and external environment), description (verbally labelling our experiences), mindful actions (acting with awareness), non-judgmental (not being overly critical of ourselves and others) and non-reactivity (not reacting impulsively to thoughts and feelings). The FFMQ-15 is the short version and has 15 items, the original version has 39. Responses are made on a 5-point Likert scale and range from 1 (never or rarely true) to 5 (very often or always true). There is a combination of direct scoring (e.g. 5=5) and reverse scoring (e.g. 5=1) to reveal a score for each facet and an overall total.

The FFMQ-15 has been found to have high validity and reliability (Baer et al., 2006; Bohlmeijer et al., 2011).

The ARSQ 2.0 is a questionnaire to assess patients' subjective experience of their thoughts and feelings at rest. The questions tap into 10-factors: Discontinuity of Mind, Theory of Mind, Self, Planning, Sleepiness, Comfort, Somatic Awareness, Health Concern, Visual Thought and Verbal Thought. The ARSQ 2.0 involves a 5-minute eyes closed rest period followed by 55 questions about thoughts and feeling that were experienced. Responses are made on a 5-point Likert scale ranging from 1 (completely disagree) to 5 (completely agree). We expect to see an increase in Comfort and a decrease in Discontinuity of Mind.

The test-retest correlations were found to be high for all 10-factors and mental health positively correlated with Comfort and negatively with Discontinuity of Mind (Diaz et al., 2013; Diaz et al., 2014).

The GAD-7 is a questionnaire to assess the presence and severity of generalized anxiety disorder (GAD). It asks about patients' experiences in the last 2 weeks in relation to anxiety. Responses range from "0" (Not at all) to "3" (nearly every day). Presence and severity of anxiety is scored as follows: 0-5 = mild, 6-10 = moderate, 11-15 = moderately severe, 15-21 severe.

The GAD-7 has been found to have good reliability, as well as criterion, construct, factorial, and procedural validity (sensitivity 89% and specificity 82%). Although anxiety and depression are closely related, factor analysis confirmed them as distinct dimensions. Also, good agreement was found between self-report and interviewer administered versions of the scale (Spitzer, Kroenke, Williams, & Loewe, 2006).

The PSS is measure of the perception of stress and measures the degree to which situations in one's life are appraised as stressful. It is one of the most widely used measures of stress. There are 10 items that tap into how unpredictable, uncontrollable, and overloaded respondents find their lives. Questions ask about feelings and thoughts during the last month in relation to stress, enquiring how often they felt a certain way. Responses range from "0" (never) to "4" (very often). Scores are then reversed and summed to reveal at total between 0 and 40. Presence and severity of stress is scored as follows: 0-13 = low, 14-26 = moderate, 27-40 = high.

The PSS has been found to have a good level of validity and reliability. (Cohen, Karmack, & Mermelstein, 1988; Roberti et al., 2006; Taylor, 2015).

The WEMWBS is a measure of mental wellbeing. There are 14 items that enquire about both the feeling (e.g. I have been feeling cheerful) and functioning (e.g. I have been feeling useful) aspect of mental wellbeing. Responses range from "0" (none of the time) to "5" (all of the time). Scores are summed to reveal a total between 14 and 70. Based on UK population samples: 14-42 = low wellbeing, 43-59 = average wellbeing, 60-70 = high wellbeing.

The WEMWBS has been used extensively worldwide and has been found to have high validity and reliability (Clarke et al., 2011; Taggart et al., 2013; Maheswaran at al., 2012).

Effects on practice adherence and skills utilization will be investigated using experience sampling methodology (a method of recording subjective experiences in daily life). Participants will respond to several short messages a day sent to their mobile phone about their daily subjective experiences. This will allow us to assess patients in the moment subjective experience rather than their retrospective subjective experience.

Qualitative assessments will be conducted during a post-intervention interview via video link. They will serve to assess patients' views on acceptability of the intervention and practices, their experience and utilization of mindfulness skills, and their views on potential barriers and facilitators of engagement. Qualitative assessments will be based on a semi-structured topic guide. The interview will last about 30 minutes. Interviews will be transcribed and subjected to thematic analysis using a framework approach.