A randomised wait-list-controlled trial is being run in a psychology department research clinic at a London University providing two four-week group interventions (one Acceptance and Commitment Therapy (ACT) and one MBSR-informed) to students presenting with mild to moderate anxiety. Pre and post measures of anxiety, depression, psychological flexibility, mindfulness, self-compassion, letter-number sequencing and trail making will be collected. Groups will be audio recorded for qualitative analysis and long term follow up outcomes will be collected.

This pilot study is designed as a randomised controlled trial comparing the effectiveness of two group interventions to a waitlist control (WLC) group: The first group is informed by Acceptance and Commitment Therapy (ACT), and the second group is informed by Mindfulness-Based Stress Reduction (MBSR). Student participants in the intervention groups will take part in either four 2-hour group sessions of ACT or MBSR-informed group interventions. Participants who are placed on the waitlist will be offered either brief ACT or brief MBSR-informed groups after 4 weeks. Both intervention and WLC groups will be administered an assessment battery before the interventions start (baseline), and soon after the intervention (post-intervention). All participants will complete the assessment battery measures at 8 weeks after post-measurement (4-week follow-up). After the completion of the 4-week follow-up measures, participants in the WLC group will be randomly allocated to either intervention groups, followed up by a post-measurement 4 weeks later after the completion of each intervention.

METHODS Therapeutic interventions: Participants of the intervention groups will be randomly allocated into either a 4- week ACT or MBSR-informed group. Instructions will be offered by the group facilitators, including discussion, reading assignments, as well as training and practice in a variety of acceptance- and mindfulness-based techniques.

ACT GROUP The ACT protocol proposed in this study has been adapted from a manual developed by Flaxman, McIntosh and Oliver (2018) for ACT training in workplace settings. This protocol has been adapted further by the authors in collaboration with Dr Kornilia Givissi and Dr Hana Villar for use in clinical settings and specifically applied to participants struggling with anxiety. This intervention combines psychoeducational and experiential practices to introduce concepts and develop skills in the six core processes of ACT. Participants will attend 4 two-hour weekly sessions of this group. The first five and last five minutes of each session will be for process measure completion. The focus of each session is detailed in the ACT protocol MBSR-INFORMED GROUP The 4-week MBSR protocol proposed in this study has been adapted from the work of Kabat-Zinn (1990), Segal, Williams, and Teasdale (2002) and has been adapted by Dr Trudi Edginton, an experienced mindfulness teacher. It has synthesised the main elements, includes all of the traditional practices and is congruent with the philosophical underpinning of the original MBSR group. This group consists of 4 two-hour weekly sessions. The first five and last five minutes of each session will be for process measure completion. The focus of each session is detailed in the MBSR-informed protocol .

Waitlist Control (WLC) group: Those assigned to the WLC group will not engage in the group interventions during the course of the intervention period. At the start of the pilot trial, they will be informed of the 4-week waiting period after which they will be randomly allocated into either intervention groups. They will be asked to complete the assessment battery measures at baseline and all follow-up timepoints.

Researcher/Practitioners: The ACT or MBSR-informed protocols in this study will be delivered by qualified and HCPC registered counselling and/or clinical psychology practitioners and are either employed or visiting lecturers in the Department of Psychology. They will all have received training in ACT and/or MBSR, and will undertake weekly clinical peer supervision to ensure fidelity to the intervention models. The research will be evaluated by the named staff members on this application and will not provide interventions but supervision to those delivering the protocols to the study participants.

Evaluation: Evaluation of the study will be conducted by the research clinic team. The evaluation will comprise of the assessment battery measures that will be self- administered at the start of the project and collected by the researcher, and therapy process measures that will be completed at the end of each session. To ensure confidentiality, measures will be de-identified and assigned a code. The researcher will remind the participants that they can choose not to complete the measures or answer any of the questions. Any paper-based measures completed by participants will be stored in a locked filing cabinet in the research clinic office until the data have been entered into a computer, after which hard copies will be securely destroyed. Data collected via tablet or other electronic devices will be stored on a City-protected cloud.

Inclusion Criteria:

• Mild to moderate anxiety

Exclusion Criteria:

• dissociation