Designing Positive Psychology Interventions for Social Media: Cross-Sectional Web-Based Experiment With Young Adults With Cancer.

Background: Young adults (ages 18-39 years) with cancer face unique risks for negative psychosocial outcomes. These risks could be lessened with positive psychology interventions adapted for social media if intervention messages encourage intentions to do the activities and positive message reactions and if young adults with cancer perceive few downsides. Objective: This study aimed to assess whether social media messages from evidence-based positive psychology interventions encouraged intentions to do the intervention activities and intended positive message reactions, overall and among sociodemographic or cancer characteristic subgroups. We also aimed to identify perceived downsides of the activity that would negatively impact the interventions' feasibility. Methods: Young adults (ages 18-39 years, cancer diagnosis ages 15-39 years) were randomized to a between-persons web-based experiment. Participants viewed a social media message with social context cues (vs not) for 1 of 2 types of intervention (acts of kindness vs social connectedness). Participants reported intentions to do the activity, along with their perceived social presence in the message (how much they felt the sense of others) and forecasted positivity resonance (whether they would experience socially connected positive emotions when doing the activity), with 5-point items. Participants also reported their self-efficacy (how certain they can do the intervention activity) with a 0-100 item and potential downsides of the activity categorically. Results: More than 4 out of 5 young adults with cancer (N=396) reported they "somewhat" (coded as 3) to "extremely" (5) intended to do the intervention activity (336/396, 84.8%; mean ranged from 3.4-3.6, SD 0.9-1.0), perceived social presence in the messages (350/396, 88.4%; mean 3.8, SD 0.7), and forecasted positivity resonance (349/396, 88.1%; mean 3.8-3.9, SD 0.8). Participants reported having self-efficacy to complete the activity (mean 70.7% of possible 100%, SD 15.4%-17.2%). Most (320/396, 80.8%) did not think of the downsides of the interventions. Messages with social context cues (vs not) and both intervention types were rated similarly (all P>.05). Black young adults reported lower intentions, perceived social presence, and forecasted positivity resonance than White young adults (all P<.001). Participants in active treatment (vs completed) reported greater intentions to do the activities (P<.001). Conclusions: Positive psychology intervention messages adapted for social media were perceived as acceptable and feasible among young adults with cancer. The social media-based messages encouraged increasing one's social connectedness and performing acts of kindness. Young adults with cancer also predicted they would have feelings of positive social engagement (positivity resonance) when doing the interventions-the key ingredient for experiencing the health benefits of these activities. This study provides promising evidence for the development of age-appropriate, highly scalable interventions to improve psychosocial health among young adults with cancer.