Mindfulness, acceptance and reflection training by text message - an effectiveness trial investigating stress-reduction in the general population of Sweden

INTERVENTION: 12 weeks of text message delivered mindfulness‐ and acceptance‐based stress‐reduction (AiM) vs 12 weeks of mental health self‐study (control). The effectiveness of a 12‐week, text message delivered, mindfulness‐ and acceptance‐based stress‐reduction course will be investigated in a semi‐blinded randomized controlled trial, in which the 12‐week course will be compared to self‐studies of mental health information. The study population will be people aged above 15 years seeking help online for stress and have access to a mobile phone. Employing a Bayesian sequential design, the study will continuously monitor the primary outcome to calculate target criteria for when to stop recruiting, allowing for avoidance of both under‐ and over‐recruitment. A measure of perceived stress (Cohen’s 10‐item version) will be the primary outcome, and mediation analysis will reveal if improvements are mediated by acquired equanimity. Follow‐up measures will be made at 3‐, 6‐ and 12 months. Effectiveness will be analyzed with Bayesian regression models, and mediation will be analyzed by using a causal inference framework. Randomization will be fully automated and computerized and neither research personnel nor participants will be able to influence allocation. Stratified block randomization (with random block sizes of 2 and 4) will be done based on self‐reported history of serious disease during childhood. CONDITION: People above the age of 15 years from the general population, who self‐identify a need for stress reduction ; Mental and Behavioural Disorders PRIMARY OUTCOME: Perceived stress is measured using the 10‐item version of the Cohens Perceived Stress Scale (PSS) at baseline, 1 month, 3 months, 6 months and 1 year SECONDARY OUTCOME: 1. Mental well‐being is measured using the Warwick‐Edinburgh Mental Well‐Being Scale (WEMWBS) at baseline, 1 month, 3 months, 6 months and 1 year; 2. Life satisfaction is measured using the 2‐item Cantrils Ladder at baseline, 1 month, 3 months, 6 months and 1 year; 3. Anxiety is measured using the General Anxiety Disorder‐7 (GAD‐7) scale at baseline, 1 month, 3 months, 6 months and 1 year; 4. Depression is measured using the Patient Health Questionnaire‐9 (PHQ‐9) scale at baseline, 1 month, 3 months, 6 months and 1 year; 5. Equanimity (mediator tested) is measured using the two‐factor equanimity scale (EQUA‐S) scale at baseline, 1 month, 3 months, 6 months and 1 year INCLUSION CRITERIA: 1. People from the general population 2. Above the age of 15 years 3. Access to a mobile phone 4. Language skills (Swedish) to comprehend study information and questionnaires