Table 3.

Characteristics of included studies on social interventions delivered at the group or individual client level

	Country	Study design	Study population	Kmet score/100 (quant.)	Kmet score/100 (qual.)	Social outcomes investigated	Key findings
Community participation studies
Chen et al 75	China	Non‐blinded RCT comparing Clubhouse model with standard care	Adults with SMI	75		Outcomes at 6 months. Primary: social functioning and self‐determination.	Clubhouse group had greater improvement in social functioning and self‐determination.
Heatherington et al 76	US	Non‐controlled pre‐post study evaluating a residential farm program	Adults with SMI	86		Outcomes at 6 and 36 months: clinical and personal recovery; community participation.	Improved community participation at 36 months.
Varga et al 77	Hungary	Non‐blinded RCT comparing community social club with case management or TAU	Adults with SMI	92		Outcomes at 6 months: social functioning and social cognition.	Community social club and case management groups had better social function than TAU. Community social club group also had better social cognition.
Moxham et al 78	Australia	Qualitative evaluation of Recovery Camp	Adults with SMI		85	Participants’ personal goals and whether met during the camp.	Goals: connectedness; developing healthy habits; challenging myself; personal recovery. Most goals reported as met.
Prince et al 79	US	Qualitative exploration of Clubhouse model	Clubhouse members (adults with SMI)		85	Exploration of benefits of Clubhouse membership and most helpful features.	Benefits: improved social skills, gaining confidence, social connection. Features: flexible, non‐judgmental culture; equality of members and staff; evening and weekend activities; skills acquisition; sharing experiences; outreach support.
Rouse et al 80	Canada	Participatory qualitative evaluation of Clubhouse model	Clubhouse members (adults with SMI) and staff		95	Explored how Clubhouse structures and ethos facilitated members’ recovery.	Structures/ethos: mutual respect, promoting self‐efficacy and autonomy, opportunities for social connection, providing purpose. Recovery: building identity and self‐respect, acquiring skills, being part of an empowered community.
Saavedra et al 81	UK	Qualitative evaluation of creative workshops in local art gallery	Adults with SMI, mental health staff, and workshop facilitator		95	Exploration of impact of workshop participation.	Main benefits: learning about artistic process; social connection; greater psychological well‐being; challenging institutional attitudes; breaking down barriers between service users and staff.
Whitley et al 82	Canada	Qualitative evaluation of a participatory video project	Adults with SMI		80	Exploration of participants’ experiences of the project.	Project well received. Main benefits: skill acquisition; connectedness; meaningful focus; empowerment; personal growth.
Smidl et al 83	US	Non‐controlled, mixed methods pre‐post evaluation of a therapeutic gardening project	Adults with SMI and staff	45	60	Outcomes at 3 months: motivation, social skills. Qualitative data from participants’ journals.	Motivation ratings improved. Most participants and staff felt the project helped with social connection and skills. Qualitative: the project gave people a sense of purpose and pride.
Family intervention studies
Kumar et al 84	India	Assessor‐blinded RCT comparing a brief psychoeducation programme with nonspecific control intervention	Key relatives of adults with SMI	69		Outcomes at completion of sessions. Primary: carer burden.	Intervention group experienced greater reduction in carer burden.
Martin‐Carrasco et al 85	Spain and Portugal	Multicentre, assessor‐blinded RCT comparing psychoeducation intervention programme with TAU	Primary family caregivers of adults with SMI	96		Outcomes at end of intervention (4 months) and 4 months later. Primary: subjective and objective carer burden.	Intervention group experienced reduced subjective carer burden at both follow‐ups. No difference between groups in objective carer burden.
Mirsepassi et al 86	Iran	Implementation study of a psychoeducation service	Adults with SMI and their family members	60		Programme development, implementation and sustainability.	Implementation affected by: low referral rate; limited resources; poor literacy; excessive distance to travel to access service.
Perlick et al 87	US	Assessor‐blinded RCT comparing carer‐only adaptation of family focused therapy with standard health education	Relatives of adults with SMI	88		Outcomes at end of intervention and 6 months later. Primary: carer burden.	Intervention group experienced greater improvement in carer burden at both follow‐ups.
Al‐HadiHasan et al 88	Jordan	Qualitative process evaluation, nested within an RCT	Adults with SMI and their primary caregivers who received the family intervention		85	Impact of family psychoeducation intervention on recipients.	Carers reported improved health, well‐being and coping. Service users reported better motivation. Both groups experienced improved self‐confidence and social interaction.
Edge et al 89	UK	Mixed methods, feasibility cohort study	African‐Caribbean adults with SMI, their relatives or “proxy” family	65	65	Feasibility of delivering a culturally appropriate family intervention to “proxy families” (peer supporters or volunteers if no family).	Intervention highly acceptable. Most service users reported improved family relationships. Relatives’ communication with service users and health professionals improved.
Higgins et al 90	Ireland	Sequential mixed methods, single group, pre‐post pilot evaluation of EOLAS programmes	Adults with SMI and their family members	45	55	All outcomes at programme completion. Service users and families: hope for the future and self‐advocacy. Family members: perceptions of available social support.	No significant changes in quantitative outcomes. Qualitative: most participants found hearing other members’ stories was helpful. Co‐facilitation by peer support workers viewed positively, but some clinician facilitators appeared to lack skills to enable peer support worker co‐facilitators to participate equally.
Higgins et al 91	Ireland	Sequential mixed methods, single group, pre‐post evaluation of EOLAS programmes	Relatives of adults with SMI	59	50	All outcomes at programme completion: confidence in ability to cope and to access help for relative; self‐advocacy; hope for the future.	Participants experienced increased confidence and hope and were satisfied/very satisfied with the program. Qualitative: increased awareness of communication within the family; value of peer support.
Lobban et al 92 and Lobban et al 93	UK	Assessor‐blinded RCT comparing online psychoeducation + resource directory (RD) with RD alone; mixed methods evaluation and economic analysis	Relatives and close friends of adults with SMI. Qualitative sample: intervention group only	100 100	65 50	Outcomes at 12 and 24 weeks. Primary: carer well‐being and experience of support. Secondary: costs of intervention and health and social care; experiences of the intervention.	No differences between groups in carer well‐being and support. Intervention cost more than RD alone and delivered no better health outcomes. Qualitative: intervention positively received. Proactive support from the peer supporters particularly appreciated.
Nguyen et al 94	Vietnam	Non‐controlled, mixed methods, pre‐post evaluation of family intervention and cost analysis	Adults with SMI and their caregivers	68	45	Outcomes at 1 year. Quantitative: service user functioning. Qualitative: intervention acceptability and feasibility. Cost analysis: service user and family income.	High participation (98%) and acceptability. Service user functioning improved, and one quarter secured a paid job. Financial burden on family decreased.
Peer‐led/supported intervention studies
Agrest et al 95	Chile	Qualitative evaluation of peer supported intervention promoting recovery	Adults with SMI		80	Feasibility and acceptability of the intervention.	Peer support workers well received and helped engagement with community resources.
Beavan et al 96	Australia	Self‐report survey of Hearing Voices Network	Adults with SMI who attended network meetings	85	75	Cross‐sectional data only. Descriptive and free‐text responses.	Positive benefits included reduced isolation, gaining social skills and improved self‐esteem.
Easter et al 97	US	Non‐blinded RCT comparing facilitation of advance directive by a peer‐support worker or a clinician	Adults with SMI under the care of an ACT team	69		Outcomes at 6 weeks. Primary: empowerment. Secondary: self‐esteem.	Modest advantage of using peer support workers in terms of empowerment and attitudes toward treatment.
Mahlke et al 98	Germany	Assessor‐blinded RCT comparing peer support + TAU with TAU alone	Adults with SMI	96		Outcomes at 6 months. Primary: self‐efficacy.	Self‐efficacy greater for intervention group.
O'Connell et al 99	US	Assessor‐blinded RCT comparing peer mentor + TAU with TAU alone	Adult inpatients with SMI, substance misuse and recurrent admissions	85		Outcomes at 9 months. Secondary: social function and sense of community.	Greater improvement in social function for intervention group.
Salzer et al 100	US	Non‐blinded RCT and qualitative evaluation of addition of peer support workers to community mental health services	Adults with SMI	69	60	Outcomes at 12 months: community participation, empowerment, therapeutic alliance. Qualitative: content of peer support.	Peer support group had greater community participation days.
Thomas et al 101	US	Sub‐analysis of intervention arm of RCT comparing peer support with TAU	Adults with SMI receiving the peer support intervention	89		Outcomes at 6 and 12 months: therapeutic alliance, empowerment and satisfaction.	Therapeutic alliance between participants and peer workers was high and positively associated with empowerment and satisfaction.
Social skills intervention studies
Favrod et al 102	France	Non‐controlled pre‐post evaluation of Positive Emotions Program for Schizophrenia	Adults with schizophrenia and severe negative symptoms	86		Follow‐up assessment point not specified. Primary: social function.	Social function improved.
Hasson‐Ohayon et al 103	Israel	Non‐blinded RCT comparing social cognition and interaction training (SCIT) vs. therapeutic alliance focused therapy (TAFT) vs. TAU	Adults with SMI under a psychiatric rehabilitation service	75		Outcomes at end of 6 month intervention and 3 months later. Primary: social function.	No difference between groups in social functioning.
Horan et al 104	US	Non‐blinded RCT comparing social cognitive skills training (SCST) delivered in vivo with SCST delivered in clinic or active control intervention	Adults with SMI	93		Outcomes at 3 months. Primary: social cognition. Secondary: social functioning.	SSCT groups both improved in social cognition. No between‐group differences in social functioning.
Kayo et al 105	Brazil	Assessor‐blinded RCT comparing social skills training with an active control intervention	Adults with treatment resistant schizophrenia receiving clozapine	93		Outcomes at 20 weeks and 6 months. Primary: negative symptoms. Secondary: social skills.	No between‐group differences in social skills or negative symptoms.

RCT – randomized controlled trial, TAU – treatment‐as‐usual, SMI – severe mental illness, quant. – quantitative, qual. – qualitative