The Effect of a Nature-based, Self-help Intervention on Mental Wellbeing

The goal of this pilot randomised controlled trial is to test the feasibility of a brief nature-based self-help psychological intervention for low mental wellbeing. The investigators want to learn whether the intervention is likely to help improve mental wellbeing and whether it is acceptable to participants. Participants will be members of the public in the United Kingdom (UK) with low mental wellbeing and the intervention lasts for four weeks. The main questions it aims to answer are: Will participants\' mental wellbeing improve after the intervention, relative to participants in a waiting list arm. Will participants find the intervention useful and acceptable to do? Participants will: Complete baseline questionnaires on demographic information and on several areas linked to wellbeing. Complete further questionnaires on wellbeing after 2 weeks and 4 weeks. Complete a questionnaire on their experience of the intervention at 4 weeks. Receive and complete a self-guided booklet and link to a webspace to complete activities that are informed by psychological principles. Receive the intervention after four weeks if they were allocated to the waiting list arm first.