Randomization
Patients were randomly allocated (1:1) using random.org to either the HP in addition to TAU group, or to a control group receiving only TAU. To reduce researcher bias, the randomization procedure was conducted by undergraduate or graduate-level psychology students who were either doing a clinical internship or were working as psychologist assistants. Participants were informed of their allocation via postal mail. Those randomized to the HP group were sent instructions about how to log on to the digital platform, with the information that they would be contacted again to complete the 10-week assessment, and those randomized to TAU were informed that they would be contacted again to complete the 10-week assessment. See Figure 
Flow diagram.