Barriers at individual and program levels – such as low motivation, logistical challenges, and mismatches between intervention content and personal goals – often led to disengagement and high attrition. Tailored interventions, flexible delivery, and collaborative design were key to meeting participants’ diverse needs and ensuring meaningful outcomes.

Low Motivation and Initial Scepticism

Low motivation [s143, s240, s288, s323, s351], initial scepticism [s266, s267, s278], and limited awareness of intervention benefits [s289, s346] posed challenges to recruitment and engagement. Programs addressed these issues using motivational interviewing [s240], peer testimonials [s25, s186], and clear, accessible information about intervention goals and outcomes. For example, Beentjes et al. (2018) [s25] described how the e-Illness Management and Recovery (e-IMR) program used peer videos to illustrate recovery journeys, encouraging participants to share their own stories and engage more actively in the process.

Unstable Living Conditions and Logistical Barriers

Unstable housing [s152, s190], transportation challenges [s375], and competing commitments [s214, s253, s274, s275, s336, s335, s361, s375, s422] frequently disrupted participation. To reduce these barriers, programs embedded services in accessible locations and addressed basic needs alongside clinical care. For example, the Shelter-Based Mental Health Services program offered mental health support within a homeless shelter, combining short-term residential care with psychosocial services [s445]. PTSD treatments delivered in familiar community settings also improved access and reduced transportation burdens [s228]. Overall, flexible delivery, personalised support, and regular follow-up helped reduce attrition [s59, s78, s185, s305].

Past Adverse Experiences, Psychiatric Symptoms, and Other Health Conditions

Mental health symptoms [s6, s43, s103, s108, s132, s170, s174, s199, s214, s273, s307, s321, s323, s336, s351, s376, s389, s422, s423, s447], physical health issues [s6, s274, s275, s323, s326, s361, s403], and substance use [s46, s141, s247] were frequently cited barriers. Some participants experienced emotional distress when discussing sensitive topics [s134, s205, s236, s250, s260, s378], which in some cases triggered symptom exacerbation [s134, s422].

Programs addressed these challenges using trauma-informed care, gradual exposure, and supportive, non-judgmental environments. For example, MERIT (Metacognitive Reflection and Insight Therapy) prioritised a collaborative therapeutic relationship to promote psychological safety [s115]. Recovery-Oriented Cognitive Therapy (CT-R) helped participants build confidence by setting achievable goals, offering supportive feedback, and celebrating progress [s177]. Cognitive Enhancement Therapy (CET) combined psychoeducation with stress-management and gradual exposure to emotionally challenging material [s132].

High Cognitive Demands and Technological Literacy Barriers

Perceived cognitive and emotional demands [s39, s205], along with technological barriers [s6, s153, s184, s186, s249, s270], hindered participation, particularly among older adults or those with limited digital literacy. Programs responded by offering user-friendly platforms [s32, s144], step-by-step manuals [s129, s435], technical support [s234], and self-paced content with varied difficulty [s243, s458]. For instance, the HARP program adapted materials to a sixth-grade reading level [s129], and the “Recovery Is Up to You” course provided workbooks for self-paced activities [s435]. Cognitive Remediation Therapy (CRT) used structured tasks that gradually increased in complexity to support skill development over time [s458].

Irrelevant Content and Misalignment with Personal Goals

Participant dissatisfaction often stemmed from a mismatch between program content and individual goals [s18, s155, s182, s442, s448]. Interventions perceived as overly academic or detached from real-life needs were frequently seen as less helpful than practical, hands-on approaches [s419, s424]. To improve relevance, programs used needs assessments, goal-setting, and real-world skill-building. For example, psychiatric rehabilitation programs emphasised independent living, individual coaching, and gradual responsibility increases, aligning recovery plans with participants’ aspirations [s225, s237, s423].

Collaboration with service users was critical for creating person-centred, flexible and adaptable interventions, allowing for adjustments in intensity, frequency and content as needed [s144, s151, s209]. Involving consumers at every stage – from conceptualisation through implementation to evaluation – facilitated shared decision-making, self-determination, and empowerment, giving individuals the confidence to take charge of their own recovery [s89, s252, s307, s452, s463]. For example, Zabel et al. (2016) [s463] highlighted co-production in Recovery Colleges - where individuals with lived experience collaborated with professionals - as a key feature that dismantled hierarchical structures and fostered equality, mutual respect, and stronger therapeutic relationships.

Challenges in Balancing Structure and Flexibility

Overly rigid interventions often failed to accommodate diverse participant goals, cognitive ability, and real-world circumstances [s6, s205, s219]. Conversely, excessive flexibility risked a loss of coherence, resulting in confusion, role ambiguity, and inconsistent implementation [s13, s383, s384, s438]. A large number of studies (n = 99) highlighted the importance of structure in maintaining program quality and fidelity. Clear objectives, standardised protocols, and consistent implementation ensured that both participants and facilitators understood the program’s goals, steps, and expectations, reducing ambiguity and enhancing comprehension and retention of critical skills [s136, s138, s142, s166, s293].

Successful programs balanced structure with adaptability. For example, a cognitive rehabilitation program for people with bipolar disorder combined structured sessions on organisation and cognitive skills with personalised schedules and tailored activities [s118]. Similarly, the IPS model designed for homeless veterans adhered to a standardised framework while allowing vocational counsellors to tailor support to participants’ goals and barriers [s254].

Interpersonal Factors and Support Networks

Lack of supportive social networks (e.g., inconsistent family involvement) increased the risk of dropout [s214, s390]. Some studies reported that families were disengaged [s194, s390], while others struggled with challenges of their own. To strengthen support, several programs offered caregiver training. For example, Psychosis REACH provided free one- and four-day sessions focused on psychoeducation, self-care, and CBT-informed caregiving skills, along with travel and lodging assistance for families [s242]. Programs like “Just Do You” included family and recovery role models in intake sessions, using arts and storytelling to reduce stigma and build trust in the treatment process [s322].

Peer support also fostered social connectedness [s20, s31, s103, s141, s245, s282, s322]. Peer facilitators helped create understanding environments by sharing lived experiences [s31, s103, s141]. However, Beavan et al. (2017) [s20] noted that while peer leadership roles were seen as empowering, some participants were hesitant due to confidence issues, fear of responsibility, or lack of leadership training.

Group settings offered benefits but also posed challenges. Some participants felt overshadowed by dominant voices [s351, s463], disengaged by didactic facilitation styles [s351], or believed their individual needs were overlooked [s445]. Others found the pressure to participate counterproductive, particularly for those not yet ready or comfortable engaging [s351]. Programs addressed these issues by training facilitators and fostering group dynamics that were safe, trusting, welcoming, and respectful.