BACKGROUND: Non-custodial judicial treatment orders aim to reduce recidivism for justice-involved people with drug and/or alcohol use problems, but health and well-being impacts are not understood. We conducted the first qualitative evidence synthesis to explore the perceived impacts on health and well-being of treatment orders and the perceived barriers and facilitators to implementation from the perspectives of justice-involved adults, their family members/significant others, and staff delivering/ mandating the treatment.

DESIGN: We searched 14 bibliographic databases (31/10/2023-07/11/2023) and conducted supplementary searches to identify qualitative evidence. Two reviewers appraised methodological limitations using CASP and assessed confidence in review findings using GRADE-CERQual. We used framework synthesis to synthesise evidence. We integrated synthesised findings with results of a complementary quantitative review investigating health and well-being effects of treatment orders.

RESULTS: We synthesised 25 studies (29 reports); 22/29 reports had moderate or high methodological limitations. Most studies (n = 20) focused on USA drug courts; none focused on alcohol interventions. Only three studies had health and well-being as their main focus. No studies involved family members. Only one study reported a theory of how treatment orders might impact health. GRADE-CERQual assessments of 13 findings were high (n = 7/13), moderate (n = 4/13), or low (n = 2/13) confidence. Justice-involved adults perceived treatment orders to reduce mortality/morbidity risk, improve sense of self and coping with emotions, to result in feeling healthier, but also to exacerbate trauma and increase stress. Coerced treatment was perceived to interfere with "therapeutic change," nonetheless it was often perceived to reduce, cease and/or stabilise illicit drug use. Justice-involved adults' challenging life circumstances were an important barrier to reducing/ ceasing substance use. Abstinence-based approaches were common but abstinence may be unrealistic. Intervention effectiveness trials rarely measured relational outcomes of importance to justice-involved adults e.g., impacts on their children, or health outcomes.

CONCLUSIONS: High-quality qualitative studies are urgently needed on the health impacts of diverse treatments orders. Treatment orders should emphasise harm-reduction treatment approaches and address participants' healthcare and social needs. Theories of how treatment orders work are needed. Unintended negative health consequences of treatment orders must be researched. Future trials should measure and report health and relational outcomes.

Study protocol registration: [CRD42023484923]. The National Institute for Health and Care Research (NIHR) Evidence Synthesis Programme (Grant: NIHR153425, project number NIHR162046) funded this study.