How can the utilisation of help for mental disorders be improved? A quasi-experimental online study on the changeability of stigmatising attitudes and intermediate variables in the process of utilisation.

Background: Epidemiological studies show that even in highly developed countries many people with depression do not seek help for their mental health issues, despite promising prevention approaches encouraging people to seek help and reduce self-stigma. Therefore, an anti-stigma intervention study to support help-seeking behaviour will be developed on the basis of the newly explicated "Seeking Mental Health Care Model".

Methods: A quasi-experimental online study will be carried out to assess the effect of different intervention variables relevant for the help-seeking process. The study is conceived as a fractional factorial design. Participants will be screened for depressive complaints (PHQ-9 sum score ≥ 8) and current psychiatric/psychotherapeutic treatment. After baseline assessment the participants will be randomly allocated into one of the 24 study groups receiving different combinations of the vignette-based intervention aiming to reduce stigma and support help-seeking. Next, relevant outcome measures will be administered a second time. In a 3- and 6-month follow-up help-seeking behaviour will be measured. Gamified elements and avatar-choice techniques will be used to heighten study immersion and adherence.

Discussion: On the basis of the project results, promising research and intervention perspectives can be developed. Results, firstly, allow for a more detailed empirical investigation and conceptualisation of the stages of mental health care utilisation, as well as an examination of theoretical approaches to stigmatisation. Secondly, our online study could provide insights for an evidence-based design and evaluation of online interventions for people with a mental illness.

Trial Registration: German Clinical Trials Register: DRKS00023557 . Registered 11 December 2020. World Health Organization, Universal Trial Number: U1111-1264-9954. Registered 16 February 2021.