Introduction: There is a need for efficacious lifestyle interventions that promote the mental health and emotional wellness of both healthy and clinical cohorts. Evidence regarding the usefulness of adding human support (i.e. guidance) to improve the outcomes of web- and mobile app-based psychological interventions for clinical populations is mixed,^1-3 however little is known about healthy cohorts.

Methods: 458 self-selected participants registered to join a 10-week, web- and mobile app-based, multimodal lifestyle intervention. The participants were randomised into three groups, differentiated by support mode: standard, who received automated emails only (S); standard plus personalised SMS messages (S+pSMS); standard plus online group discussions (S+OGD). At pre- and post-intervention, the participants completed the following measures: the ‘mental health’ and ‘vitality’ sub-scales from the Short Form Health Survey (SF-36); Depression Anxiety and Stress Scales (DASS-21); Satisfaction With Life scale; and Flourishing scale.

Results: 320 participants (S, n=103; S+pSMS, n=114; S+OGD, n=103) completed the study. Significant within-group changes were recorded from pre- to post-intervention in all groups for every outcome measure (PP=0.77), vitality (P=0.65), depression (P=0.93), anxiety (P=0.25), stress (P=0.57), satisfaction with life (P=0.65) or flourishing (P=0.99). Attendance at the weekly online group discussions was poor, but those who attended seven or more of the ten sessions experienced significantly better outcomes than those who attended less than seven.

Conclusions: The web- and mobile app-based, lifestyle-focused, mental health intervention enhanced measures of mental and emotional wellbeing among a healthy cohort, irrespective of the mode of human support. Supplementing a psychological intervention with an online group discussion might improve outcomes, when attendance is optimised.