Preliminary Testing and Development of a Short Digital Intervention for Patients on Waiting Lists for Psychological Treatment

The goal of this randomized pilot feasibility trial is to assess the feasibility and further develop a single-session digital mental health intervention for patients on waiting lists for psychological treatment. The main aims are: 1. To evaluate the feasibility and acceptability of the study procedures and the digital single-session intervention. 2. To gather quantitative and qualitative feedback on the intervention to inform further development. 3. To collect preliminary data to refine the analysis plan for a main trial. Researchers will compare two different versions of the intervention (one longer and one shorter) with two control conditions (one active and one passive) to see if the study is feasible. Participants will be randomized to one of the four conditions, do a short digital mental health intervention and fill out 4 questionnaires across a 5 week period.