Table 2.

Summary of intervention characteristics and findings.

Author/year	Duration	Theory/model	Characteristics of intervention	Comparison group	Additional support/facilitators	Mental health outcomes	Key findings
Firth et al., 2017	8 weeks	Wellness intervention informed by transtheoretical model of behavior change. Aimed to increase awareness of specific tools necessary to engage cognitive and behavioral processes of change.	• This intervention involved a private Facebook group that revealed 1–2 new statuses each day for 8 weeks targeting each of the stages of change from the TTM (precontemplation, contemplation, preparation, action, and maintenance).	Static Facebook page (96 statuses were already posted)	NA	Anxiety (OASIS)	• Significant decrease in anxiety in the dynamic FB group from pre to post (p = .003). • Significant group-by time interaction (p = .03).
Greer et al., 2019	4 weeks	Positive psychology intervention based on broaden and build theory and stress and coping theory. Aimed to deliver cognitive and behavioral skills (e.g., acknowledging positive events, gratitude, positive reappraisal, acts of kindness, mindfulness, personal strengths, attainable goals) to reduce psychosocial distress.	• Vivibot is an automated (decision-tree-based) chatbot delivered via Facebook messenger. • Included seven conversational teaching lessons and seven practice lessons (noticing and acknowledging positive events, savoring positive events, gratitude) repeated 3× to create 28 days of content. • Interactions were dyadic, between participant and bot and included daily emotion ratings, video, survivor material, and periodic check-ins.	Waitlist control (Access to intervention after 4 weeks)	NA	Depression, Anxiety (PROMIS)	• No significant between group differences on depression (p = .77) or anxiety (p = .09).
Watkins et al., 2020	5 weeks	Targeted behavioral health intervention informed by social determinants of health, social cognitive theory, and theories of social networking/support. Aimed to promote mental health, progressive definitions of manhood, and social support	• Young Black Men, Masculinities, and Mental Health (YBMen) is social media-based psychoeducation intervention facilitated through private Facebook group. • Included culturally sensitive prompts referencing popular culture to encourage action plans development and promote group problem-solving. • Prompts were delivered via moderators, with facilitated group discussion including content/posts shared daily, likes, social interaction/replies, daily discussion questions.	NA	Moderator involved in FB group	Depression (PHQ9, GMDS); Secondary: Conformity (CMNI) and Social support (ISEL)	• Significant decrease in depressive symptoms from pre to post via PHQ9 [Pre: 7.55(4.75), Post (PHQ-9): 5.50(4.26)] (p < .01; z = −2.05) and GMDS [Pre: 10.15(6.45), Post: 8.11(6.42)] (p < .05, z = −1.76).
Yu et al., 2020	2 weeks	Positive psychology interventions based on character strengths and virtue theory, savoring theory, and the “three good things” intervention. Photo intervention aimed to promote emotional sharing, social support, and happiness using self-disclosure. Gratitude intervention aimed to promote the expression of gratitude and to improve emotional status.	• Two Facebook interventions: “Photo diary” group was instructed to take and post photos to exercise strength and virtues. “Expression of gratitude” group was instructed to post a declaration of gratitude to someone on their Facebook wall. • Posting for both groups was meant to occur every 2–3 days, and users could then receive social support and “likes” from their Facebook friends.	Placebo control (assessment completion, no intervention)	NA	Depression (CES-D) Secondary: Happiness (GHS)	• Significant between group effect on depression for photo group, compared to control (post-test p = .002, 4w follow-up p = .01). • No effect for gratitude group, compared to control (post-test p = .07, follow-up p = .08). • Significant effects at follow-up for happiness in both groups (p = .02; p = .04).
Pailler et al., 2020	10 weeks	Meaning-based intervention adapted from a manualized meaning-centered psychotherapy intervention. Aimed to help cancer patients sustain and enhance a sense of meaning, purpose, and peace through facilitating social sharing, narrative, and creativity.	• Photographs of Meaning Program for Adolescent and Young Adult cancer patients and survivors (POM-AYA) is delivered through the mobile application, Pixtori. • Included weekly emails or text messages to introduce participants to theme and encourage participation. • Participants posted photos to the cohort portal 2× per week, where they could be viewed and interacted with by others.	NA	Moderator involved to facilitate engagement (text, email)	Depression (BDI-II) Secondary: Quality of Life (Peds), Spiritual Well-being (FACIT-Sp)	• Significant decrease in depression (p = .02). • Significant increase in quality of life (p = .02). • No effect for spiritual wellbeing (p = .34).
Asbury et al., 2018	10 weeks	Online journal intervention informed by socioemotional selectivity theory. Aimed to strengthen family connections through supporting self-disclosure of feelings and thoughts about everyday life events.	• FamilyeJournal is purpose-built group journaling platform. • Participants and family members formed a closed group that received weekly prompts from researchers to reflect on thoughts and feelings. Family members could then reply to and comment on participant responses, ideally 3× per week. • Platform revealed responses to prompts after active engagement with prompts to discourage lurking.	No descriptor	NA	Depression, Anxiety (DASS)	• Significant between group difference for depression, with treatment showing reductions. • No significant difference in anxiety.
Radovic et al., 2018	6 weeks	Psychoeducation and social support intervention aimed to increase mental health literacy.	• Supporting our valued adolescents (SOVA) is a moderated anonymous blog-based social media website. • Included researcher-developed posts delivering positive content; motivational quotes or videos; psychoeducation on anxiety and depression; mental health resources via website links; question prompts to promote discussion; group sessions; 24/7 moderation. • Participants could respond and comment on peers' posts.	NA	Site moderation via trained peer moderators and clinical graduate students and clinicians	Depression (PHQ9), Anxiety (SCARD-C) Secondary: Positive Youth Development (PYDSF)	• Significant pre- to post (6 wk) difference in depression (p = .04). • Significant pre- to post (6 wk) difference in PYD (p < .001). • No effect on anxiety (p = .34).
Karim et al., 2021	3 months	Strengths-based approach focused on self-disclosure, emotion regulation, meaning making and social support, aimed to increase psychological health and positive functioning.	• The SOVA Blogging Ambassador Program is an intervention accompanying SOVA. • Participants create blog posts and share with the online community where they can then receive peer support. • Participants were asked to write one blog post a month and comment at least four times a month on other blog post.	Natural group comparison (e.g., those who blogged and those who did not)	Site moderation via trained peer moderators and clinical graduate students and clinicians	Depression (PHQ9), Anxiety (SCARD-C) Secondary: self-esteem (RSE), Positive Youth Development (PYD)	• No significant effect for main outcomes depression (p = .41) or anxiety (p = .22). • Significant increase in self-esteem (p = .01, d = 0.45). • Significant increase in PYD (p = .002, d = 0.62) and confidence (p = .002, d = 0.60).
Ludwig et al., 2021	12 weeks	Positive psychology and mindfulness intervention informed by Cognitive Behavioral Therapy. Aimed to foster social connection and deliver psychoeducation.	• Horyzons is a MOST intervention. • Included psychoeducation modules; Discussion boards e.g., The Café (a wall/newsfeed), Talk-It-Out (a forum to discuss specific issues and go through problem-solving steps), Team Up (personal goal tracking and sharing). • Moderators tailored content through weekly messaging.	NA	Moderator for supportive accountability and treatment and goal tailoring (clinical, peer)	Depression (BDI-II) Psychotic Symptoms (Positive and Negative Syndrome Scale & Brief Symptom Inventory) Secondary: Psychological Wellbeing	• Improvements in psychosis related symptoms (neg: d = −0.19; pos: −0.03) • Decrease in depressive (d = 0.04) • Increase in psychological well-being (d = 0.011)
Alvarez-Jimenez et al., 2018	8 weeks	Informed by strengths-based therapy (broaden and build) and self-determination theory. Aimed to improve social functioning.	• MOMENTUM is a MOST intervention. • Included psychoeducation modules; Discussion forums e.g., the Cafe (a wall/newsfeed); Talk-It-Out (a forum to discuss specific issues and go through problem-solving steps); Behavioral tasks (“Do Its”); Peer and expert moderation. • Moderators tailored content through weekly messaging.	NA	Moderator for supportive accountability and treatment and goal tailoring (clinical, peer)	Depression (MADRS); At risk mental states (CAARMS) Secondary: Subjective well-being (SWLS), Perceived stress (PSS)	• No significant effect for depression. • Significant effects on targets (e.g., mindfulness (p = .04, d = 0.66), strengths use (p = .03, d = 0.70) and social functioning (p < .001, d = 1.83)).
Rice et al., 2018	12 weeks	Positive psychology, mindfulness, and strength-based intervention designed as a supplement to face-to-face therapy and aimed at relapse prevention through the development of social support and skills.	• Rebound is a MOST intervention. • Included psychoeducation modules; Discussion boards e.g., Talk it Out (a forum for problem-solving); Behavioral tasks (“Actions”) • Moderators tailored content through weekly messaging.	NA	Moderator for supportive accountability and treatment and goal tailoring (clinical, peer)	Depression (MADRS) Secondary: Functioning (SOFAS), Strength use scale, Social connectedness, Social support, Worry, Anxiety	• Significant decrease in depression scores MADRS (p = .014, d = 0.45). • Nonsignificant increase in strength use (P = .09, d = 0.29). • All other variables not significant.
McEnery et al., 2021	8 weeks	Informed by integrated CBT model for Social Anxiety Disorder, aimed at psychoeducation and social support for social anxiety.	• EMBRACE is MOST intervention. • Included psychoeducation modules with evidence-based therapeutic content delivered via comics; Discussion board with “talking points”; Behavioral experiments (“Actions”); Peer and expert moderators. • Moderators tailored content through weekly messaging.	NA	Moderator for supportive accountability and treatment and goal tailoring (clinical, peer)	Social Anxiety (LSAS; SIAS), Depression and Stress (DASS) Secondary: Loneliness (UCLA)	• Significant decrease in social anxiety via SIAS (p = .0005 d = −1.70) and LASA (p = .002, d = −1.35). • No significant effects for depression (p = .50, d = −0.22) or loneliness (p = .48, d = −0.23).
Alvarez-Jimenez et al., 2020	1–9 weeks	Strengths-based psychosocial intervention meant to be a supplement to face-to-face treatment, aimed at improving conditions for high-risk adolescents.	• MOST+ is an integrated version of the MOST intervention that included real-time clinician delivered web chat counseling. • Included psychoeducation modules with evidence-based therapeutic content delivered via comics; Discussion forums e.g., the Cafe (a wall/newsfeed); Talk-It-Out (a forum to discuss specific issues and go through problem-solving steps); Behavioral tasks (“Do Its”); Peer and expert moderation; on demand web chat with clinicians. • Moderators tailored content through weekly messaging. • Peer-to-peer networking components were enabled only for those with low-risk scores.	Partial vs full access (full includes peer to peer social networking)	Moderator for supportive accountability and treatment and goal tailoring (clinical, peer); On demand counseling	Depression (PHQ9) Secondary: Psychological Distress (K10); Perceived Stress (PSS); Mental wellbeing (WEMWS)	• Significant decrease in depression (p = .008, d = −0.29). • Significant decrease in psychological distress (p < .001, d = −0.39) and perceived stress (p < .001, d = −0.44). • Significant increase in mental wellbeing (p < .001, d = 0.51).
Bailey et al., 2020	8 weeks	Cognitive-behavioral intervention informed by the interpersonal theory of suicide. Aimed at providing psychoeducation and exercises related to mindfulness, self-compassion, mental health strengths.	• Affinity is MOST intervention delivered as a supplement to traditional face-to-face treatment. • Included psychoeducation modules with evidence-based therapeutic content delivered via comics; Discussion boards e.g., the Cafe (a wall/newsfeed); Talk-It-Out (a forum to discuss specific issues and go through problem-solving steps); Behavioral tasks (“Do Its”); Peer and expert moderators. • Private direct messaging function between users.	NA	Moderator for supportive accountability and treatment and goal tailoring (clinical, peer)	Suicidal Ideation (ASIQ), Depression (PHQ9); Secondary: Interpersonal Needs (INQ)	• Significant decrease in suicidal ideation (p = .033, d = −0.57). • Significant decrease in depression (p = .016, d = −0.94). • Significant effects on targets (thwarted belongingness p = .006, =.96; perceived burdensomeness p = .005, d = −0.52).
Rice et al., 2020	12 weeks	Psychosocial and cognitive behavioral intervention aimed to improve symptoms and promote social connectedness among young people with social anxiety.	• Entourage is a MOST intervention, adapted for young men. • Included psychoeducation modules targeting cognitive strategies with evidence-based therapeutic content delivered via bespoke comics; Discussion boards e.g., the Wall (an open forum); Talking Points (prompts to discuss the symptoms depicted in comics); Talk-It-Out (a forum to discuss specific issues and go through problem-solving steps); Behavioral tasks (“Actions”) • Moderators tailored content through weekly messaging.	NA	Moderator for supportive accountability and treatment and goal tailoring (clinical, peer)	Depression and suicidality (PHQ9; MDRS), Social Anxiety (LSAS) Secondary: Wellbeing (SWEMWBS)	• Significant decrease in anxiety (p < .001, d = 0.73) • Significant decrease in depression and suicidality (PHQ-9 full scale: p < .001, d = 0.66; suicidality item: p = .026, d = 0.27) • Significant increase in wellbeing (SWEMWBS; p < .001, d = 0.50).

Note. NA = not applicable; MOST = Moderated Online Support Therapy; CBT = Cognitive Behavioral Therapy.