Therapists at the Grand Bahama Resilience Center (GBRC) will be trained to deliver Problem Management Plus (PM+), a WHO intervention. Then, those therapists will deliver PM+ (5 one-on-one skills-based sessions) to a total of 50 adult clients experiencing mild to moderate mental health difficulties (excluding anyone with cognitive difficulties or psychosis). Participants will complete (de-identified) self-report survey assessments before PM+, after PM+, 3 months later, and 6 months later. After receiving 5 sessions of PM+, participants will be randomized to either receive a one-time booster session of PM+ (to be co-created by the PI and the GBRC providers) three months later or to a control group which will receive a phone call reminding them that they will receive their third assessment soon.

This mixed-methods study will consist of three overlapping phases. First, GBRC counselors will be trained to deliver PM+ ("GBRC providers"). After some experience with PM+ delivery and practice, researchers from The New School for Social Research will collaborate with GBRC providers to develop a protocol for a one-time PM+ booster session. Third, after receiving PM+, study participants will then be randomized to-at approximately three months post-PM+ -either receive the PM+ booster session, or to receive a phone call reminder of the upcoming electronic survey (the control group).

Fidelity to the intervention and booster session protocols will be measured via self-report checklists to be submitted by the provider at the conclusion of each session. After screening and informed consent, participants will be assessed for all outcome measures prior to receiving PM+, approximately one week post-PM+, approximately three months post-PM+, and approximately six months post-PM+. Qualitative interviews with participants will be conducted approximately one week after receiving the booster session, or one week after completing the three-month follow-up for control group participants, and at the six-month follow-up. Qualitative interviews with providers will take place after delivering the PM+ booster session and at the conclusion of data collection. An IRB application outlining all portions of the study will be submitted to BRANY through The New School for Social Research in the fall of 2024. Data collection will not commence until IRB approval is secured.

Participants Randomization will occur at the individual level. Participants will be adults (18 years or older) who reside in Grand Bahama and are recruited from visitors to the Grand Bahama Resilience Center (GBRC) in Freeport, Grand Bahama. Though PM+ is a transdiagnostic intervention, and therefore not intended to target specific disorders or symptoms, it is designed to help individuals who are experiencing psychological distress. The WHO PM+ manual recommends assessing potential PM+ clients using a measure of functioning such as the WHO disability assessment (WHODAS 2.0) and a measure of emotional distress such as the General Health Questionnaire (GHQ-12) or combining the Patient Health Questionnaire (PHQ-9) and the General Anxiety Disorder-7 (GAD-7) scale (WHO, 2016). The manual suggests using a cut-off score of ≥17 for the WHODAS and ≥10 for the PHQ-9 for inclusion, but does not offer guidance for other measures. Several past studies have used a cutoff score of ≥3 for the GHQ and the ≥17 for the WHODAS as inclusion criteria. Others have used the Kessler Psychological Distress Scale as a measure of emotional distress. For this study, following experiences of PM+ implementation in New York City, the Patient Health Questionnaire-4 (PHQ-4) will be used to assess for emotional distress and the self-report version of the Global Assessment of Functioning (GAF) will be used as a measure of functioning. Participants will be eligible for the study if they score ≥3 on the PHQ-4 and ≤90 on the GAF. Exclusion criteria will follow guidelines from the WHO PM+ manual and will include acute suicidality operationalized as "high risk" on the Columbia Suicide Severity Rating Scale (C-SSRS), active psychosis, or any impairment that would prohibit one from being able to engage in the intervention (e.g. cognitive disorder, substance use disorders; WHO, 2016). Procedure PM+ Provider Training Six experienced counselors working at the GBRC will be recruited as PM+ providers. Since these providers currently deliver counseling to community members, they will be referred to as "providers" rather than the more common term "helper" which typically connotes a non-mental health professional or a lay provider. Providers will undergo a 12-hour remote PM+ training, with weekly supervision meetings that will include ongoing PM+ education, expert supervision, and peer support. If a therapist decides to join the study at a later date, another 12-hour remote PM+ training will be conducted by the PI. The intensive training will take place between August and September of 2024 and will cover the PM+ protocol and procedures detailed in the WHO PM+ manual and will include modules on conducting the PSYCHLOPS assessment and suicide screening. Common therapeutic factors will be briefly noted, however, due to the experience level of the providers, this and other introductory material relating to working with clients in distress will be condensed. Researchers have found that 12 hours of PM+ helper training is sufficient for master's level social work students, therefore the same length should suffice for this group of providers. Training will include education on PM+ session agendas, strategies and rationales, and provider self-care. Competency and fidelity will be assessed pre- and post-training using the Ensuring Quality in Psychological Support (EQUIP) tool, a competency evaluation tool designed by the WHO specifically for task-sharing interventions such as PM+. Since its launch in 2022, the EQUIP tool has been used to assess provider competency in 36 countries throughout the world.

Booster Session Development Following training and initial delivery of PM+ to at least two clients, around approximately November-December 2024, researchers from The New School for Social research will meet with GBRC providers to develop a curriculum for a one-time PM+ booster session. The booster session will include a review of PM+ strategies and administration of Psychological Outcomes Profile (PSYCHLOPS) interview. The protocol and additional components of the booster session will be developed together with the GBRC providers, who are members of the Bahamian community and have experience delivering mental healthcare with the target population. Principles of CBPR will be used to ensure equitable contribution to all aspects of the protocol development. A deliverable of a supplementary chapter to the WHO PM+ manual will be created with authorship shared by academic and community partners.

Pilot Trial GBRC providers will recruit interested potential participants from their current clients and from their counseling waitlist. Upon obtaining IRB approval, approximately around early November 2024, eligible participants who complete informed consent will be invited to complete a baseline assessment in the form of a self-report Qualtrics survey. GBRC therapists will recruit particpants and will obtain informed consent from participants. Participants will then be assigned to a GBRC provider to receive PM+. As this study will be investigating the feasibility and acceptability of a booster session for clients who received the full 5-session course of PM+, both treatment arms will receive individual PM+ after enrollment. All participants will be emailed a post-treatment survey approximately one week after receiving PM+ (6-8 weeks after baseline).

Upon completing the fifth session of PM+, participants will be randomly allocated to either the booster group (i.e. treatment group) or the control group using block randomization. Blocks of four will be used and a random number generator will be used generate the block assignments. This ensures that providers are blinded to treatment groups during initial PM+ delivery (since they will not yet have been assigned) and it ensures that participants who do not complete PM+ are not included in randomization since they will not be eligible to continue in the study. Participants will be blinded to their allocated group (i.e. treatment or control) until they complete their final (6-month-follow-up assessment) or in the case that they drop out of the study. Blinding is necessary to the study to avoid a placebo effect for those in the treatment group. If participants were aware of their study group they may be influenced to practice or engage more with the intervention than if they are blinded to their condition. Moreover, because both groups will be contacted by their provider three months following the intervention-the control group for a phone call reminder of the upcoming third assessment, and the intervention group to conduct the booster session-the risks of harm by blinding are extremely low. All participants will be made aware of their group allocation (if applicable) at the conclusion of their involvement in the study and no later than July 31, 2026.

Participants who are randomized to the control arm will terminate treatment after their fifth session of PM+, and will be notified that they should complete three more online assessments. They will be told that they will receive the first of the remaining assessments in approximately one week, and to expect a phone call reminding them of the second of the remaining assessments in approximately three months.

Participants who are randomized to the PM+ with booster arm will meet with their provider approximately three months (beginning around March 2025) after their final PM+ session (17-19 weeks after their first PM+ session) for a one-time booster session. To ensure proper recollection of the booster session, a portion of the qualitative interviews with participants will take place one to three weeks after receiving the booster session of PM+. All participants will receive follow-up assessments approximately 17-19 weeks after their baseline assessment (3-month follow-up) and approximately 28-30 weeks after their baseline assessment (6-month follow-up). All follow-up assessments are to be completed by April 2026.

Qualitative interviews with providers will be conducted by research colleagues. Effort will be made to ensure that these interviewers are versed in cultural humility and ideally familiar with the Bahamian community. Client interviews will be conducted by trusted members of the Grand Bahama community including advanced social work students who have familiarity with PM+ and other Bahamian therapists not involved in the proposed study. Interviews with participants will take place on a rolling basis approximately one to three weeks after completion of the study protocol. Final qualitative interviews with providers will be completed no later than February and March 2026.

The GBRC will provide PM+ (without booster session) to clients regardless of involvement with the study. Clients who wish to receive PM+ but do not wish to participate in the study will be able to access that care and will not be penalized in any way. Study participants will not be prioritized over non-participant PM+ clients. Non-participant PM+ clients will receive standard PM+ according to the WHO manual, without the booster session as the booster session has not been formally studied and is therefore not currently evidence-based. Accordingly, clients who do not consent to participate in the study will not receive that experimental part of the program.

Inclusion Criteria:

• Adults of 18 years or above

  • English-speaking
  • A score of <91 on Global Assessment of Functioning

• Located in the Bahamas

Exclusion Criteria:

• ● Imminent suicide risk (assessed at screening using Columbia Suicide-Severity Rating Scale, see document titled " Screener updated 10-30- 24")

  • Severe mental disorder (e.g. psychotic disorders)
  • Severe cognitive impairment (e.g. severe intellectual disability or dementia)

Because the intervention and control groups involve receiving or not receiving a booster session, neither participants nor providers can be blinded. Because the administration and data collection is being completed by the PI, who is also responsible for study administration, the PI cannot be blinded. Instead, randomization occurs after delivery of PM+ to avoid bias in PM+ delivery, and contact between the study administrator is limited to emailing questionnaires (with standardized language that does not differ between groups).