Authors' objectives: To systematically review evidence of the clinical effectiveness of psychosocial interventions for adults with substance use disorder that have a co-occurring common mental health disorder or borderline personality disorder. To identify papers that estimate the cost-effectiveness of interventions for patients with substance use disorder and common mental health disorder or borderline personality disorder. People with alcohol or drug use disorders can have a co-occurring mental health disorder. The National Institute for Health and Care Excellence has produced guidance on treating people with alcohol or drug use disorders with a co-occurring serious mental health disorder; however, this does not cover people whose mental health disorder is less severe. To systematically review evidence of the clinical effectiveness and estimate the cost-effectiveness of psychosocial interventions for adults with substance use disorder (SUD) that have a co-occurring common mental health disorder (CMD) or borderline personality disorder (BPD).

Authors' results and conclusions: Of 5420 unique records, 30 systematic reviews were included in the clinical review. The methodological quality of the reviews was generally good. Most of the interventions and many of the active comparators studied resulted in some improvement for patients. Most reviews focused on depression, anxiety or post-traumatic stress disorder; there were some looking at mixed common mental health disorder or borderline personality disorder. There was much heterogeneity both between reviews, and between the randomised controlled trials within the reviews. The results suggested integrated treatment for co-occurring diagnosis patients may be better for common mental health disorder outcomes than treatment as usual of parallel uncoordinated services. One study was identified that met the cost-effectiveness criteria. However, this reported results alongside a clinical study and was not a modelling paper. The illustrative model should aid future researchers. No implications for current practice could be recommended due to heterogeneity of reviews/randomised controlled trials within reviews. Systematic review of clinical effectiveness Database searches identified 5416 unique records, and an additional 4 records were added from bibliography searching. Thirty systematic reviews of clinical effectiveness were included. Most reviews focused on depression, anxiety or post-traumatic stress disorder, while some evaluated mixed CMD or BPD. Three reviews included RCTs from the UK. The methodological quality of the reviews was generally good. Review evidence was found for the interventions: cognitive–behavioural therapy; peer support; motivational interview; supportive counselling; psychotherapy; behavioural therapy including dialectical behavioural therapy; seeking safety; trauma-focused therapy; acceptance and commitment therapy; self-management support; contingency management, that is incentivised or compensated work therapy; mindfulness; eye movement desensitisation and reprocessing; music therapy; case management. Some of the interventions were delivered via computer or text message (digital interventions), and some were delivered as brief interventions. There was also a review investigating the colocation of services. Most of the interventions and many of the active comparators studied resulted in some improvement for patients on substance use outcomes and/or mental health outcomes. There was much heterogeneity both between reviews and between the RCTs within the reviews. There was heterogeneity in populations (type and severity), interventions and outcome measures, as well as in settings, how interventions or comparators were delivered, and treatment intensity and retention. This made it difficult to reach an overall conclusion about which therapies were best. Most reviews stated the results were not generalisable across all populations or settings. Integrated treatment (treating both SUD and CMD/BPD) was usually better than treating one condition alone, and sometimes better than parallel treatments (separate, unco-ordinated services for SUD, and either CMD or BPD). There was limited evidence assessing sequential treatment (with either SUD or CMD/BPD treated first), but this suggested it was similarly effective to integrated treatment. No implications for current practice could be recommended due to heterogeneity of reviews/RCTs within reviews. No relevant papers were identified that used modelling techniques to assess the cost-effectiveness of interventions for patients with SUD and a common mental health illness. The research group therefore provided guidance on how cost-effectiveness could be estimated using as an example, DEAL compared with control. Future research comparing integrated with parallel or sequential treatment, with follow-up of 6 months or longer, and sample size large enough to encompass dropout, may be beneficial.

Authors' methods: An umbrella review (a systematic review of systematic reviews) for clinical effectiveness was conducted. Systematic database searches [MEDLINE, EMBASE, PsycInfo® (American Psychological Association, Washington, DC, USA), Cochrane Database of Systematic Reviews, and Web of Science] were carried out in February 2024. Inclusion criteria: Adults with substance use disorder and common mental health disorder or borderline personality disorder; psychosocial interventions (with or without pharmacological therapies); comparators psychosocial treatments, treatment as usual, waitlist/no treatment; systematic reviews of randomised controlled trials. Data, including critical appraisal, were extracted into a standardised form by one reviewer, and checked by another. Data were discussed in a narrative review. A literature review of MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and EconLit were undertaken to identify cost-effectiveness papers. An illustrative model was constructed to show how cost-effectiveness could be calculated if data were available. Heterogeneity made it difficult to reach an overall conclusion about which therapies were best. Most reviews stated the results were not generalisable across all populations or settings. There were few reviews of borderline personality disorder; or of common mental health disorder other than anxiety/depression/post-traumatic stress disorder. Systematic review of clinical effectiveness An umbrella review (a systematic review of systematic reviews) was conducted. Data sources Searching of electronic databases, including MEDLINE, EMBASE, PsycInfo® (American Psychological Association, Washington, DC, USA), Cochrane Database of Systematic Reviews, and Web of Science; plus contact with experts in the field; and scrutiny of bibliographies of retrieved papers. Systematic database searches were carried out in February 2024.

Project Status: Completed

URL for project: https://www.journalslibrary.nihr.ac.uk/programmes/hta/NIHR166951

Year Published: 2026

URL for published report: https://www.journalslibrary.nihr.ac.uk/hta/GJES1821

URL for additional information: English

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: England, United Kingdom

DOI: 10.3310/GJES1821

Organisation Name: NIHR Health Technology Assessment programme

Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK

Contact Name: journals.library@nihr.ac.uk

Contact Email: journals.library@nihr.ac.uk