Investigators will adapt the Brief Social Behaviour and Network Therapy (B-SBNT) intervention developed to facilitate recovery among people receiving medication-assisted treatment for opioid use disorder in the United Kingdom. The B-SBNT involves families and the wider social networks of people receiving medications for opioid use disorder to support recovery. Key components of the intervention include: mapping the social networks of clients; inviting others identified through the mapping to participate in the intervention; building communication strategies with network members; and developing joint activities with network members. In the original B-SBNT, the intervention is delivered by therapists/clinicians who undergo training. Investigators will pilot test the adapted version of this intervention with a maximum of 80 people: 20 current clients receiving methadone maintenance treatment (MMT) at the Muhimbili National Hospital (MNH) Medically-Assisted Treatment (MAT) Clinic and up to 60 social support persons identified by recruited MMT clients. The pilot will assess the social network intervention's acceptability and feasibility.

Investigators will conduct a small pilot of the adapted social network intervention to assess its acceptability and feasibility. The study team will pilot test the adapted version of this intervention with a maximum of 80 people: 20 current clients receiving methadone maintenance treatment (MMT) at the Muhimbili National Hospital (MNH) Medically-Assisted Treatment (MAT) Clinic and up to 60 social support persons identified by recruited MMT clients.

MNH MAT clinic staff will compile a list of clients who have tested positive for heroin, cannabis, and alcohol based on monthly urine screen in the past 3 months or random alcohol breathalyzer test in the past 3 months. The list will be stratified by HIV status to obtain equal number of MMT clients with and without HIV. From the list, the research team will randomly select 10 clients with HIV and 10 clients without HIV. MNH MAT clinic staff will introduce the study to the selected MAT clients who meet study eligibility and refer those interested in participating to the study team.

During the social mapping session of the intervention, MMT client participants will be asked to identify up to three people who provide the participant with support an invitation to participate in the intervention. MMT clients will be provided a letter to give to each of the social support persons identified and will provide the study team with the phone numbers of the social support persons, if available. The recruitment letter will include the contact information for the local co-PI. If a phone number for a social support person is provided, the study team will attempt to contact the identified social support person up to three times. The study team will only contact social support persons identified by participating MMT clients after the MMT client has informed the social support person of the study and the social support person is expecting to hear from study staff. The study team will confirm with the MMT client that social support persons have been informed of the study through the recruitment letter and/or vocally. Once contact with the identified social support person is made, a member of the study team will introduce the study to the social support person and invite the social support person to participate in the study.

After obtaining informed consent, MMT clients and the identified social support person(s) will complete a pre-intervention survey. The survey with MMT clients will include questions on socio-demographics, substance use behaviors, methadone treatment, stigma experiences, coping skills, and social support. For questions on social network members, MMT clients will be asked not to specify names of family, friends, other MMT clients, or other important people in the participants lives. Rather, the participants will be asked to use nicknames, initials, or relationships (e.g., "mother," "sister," "uncle," etc.) to identify important people. The survey with social support persons will include socio-demographic questions as well as questions on interactions with the MMT client who was identified as a social support person, substance use behaviors, methadone treatment, and knowledge and attitudes towards substance use disorders and people with a substance use disorder. The pre-intervention survey is expected to last approximately 15 minutes (for social support persons) and 20 minutes (for MMT clients). MMT client participants will then attend seven sessions over the course of six weeks. Social support persons will attend up to five sessions over the course of six weeks.

Participant attendance will be recorded for each session. Members of the study team will observe sessions and take notes on intervention fidelity and delivery using a semi-structured form. After each session, participants will be asked to complete a brief exit survey to assess satisfaction with the session. The exit survey will be administered by the intervention counselor. At the end of the pilot, the study team will conduct a post-intervention survey with MMT client participants and the participating social support persons. The post-intervention survey will include similar questions to the baseline survey but will also include questions to gauge acceptability and satisfaction with the intervention, experiences with social and income-generating activities, and suggestions for changes to the intervention. The post-intervention survey is expected to last between 15 minutes (for social support persons) and 20 minutes (for MMT clients).

The investigators will also conduct 25 follow-up qualitative, in-depth interviews with 10 MMT client participants, 10 social support person participants, and all 5 intervention counselors, about one month after the trial. The investigators will purposively sample participants based on attendance in sessions and based on responses to survey questions, so that the investigators can obtain a sample of individuals with various experiences with the program. Study interviewers will use a semi-structured interview guide to facilitate the discussion. The guide will include questions on experiences with the program (what worked and what could be improved), how well counselors followed the intervention manual, what clients learned, how clients incorporated lessons learned in the clients daily lives, and changes in the quality of relationships with social support persons and other people in the client's lives. Interviews are expected to last about 45 minutes and will be audio-recorded with participant permission.

Inclusion criteria for MMT client participants in the intervention pilot:

• 18 years old or older,
• currently enrolled in the MAT program at the Muhimbili MAT clinic,
• prescribed methadone for the past 3 months,
• received a positive test result for heroin, cannabis or alcohol use in the past 3 months,
• provide consent for trial participation.

Inclusion criteria for social support persons in the intervention pilot:

• 18 years old or older,
• identified as a social support person of a MMT client participating in the pilot trial
• lives in Dar es Salaam,
• provide consent for trial participation.

Exclusion Criteria:

• Does not meet inclusion criteria

This is pilot trial is intended for assessment of feasibility and acceptability. Study investigators will make aggregate data from the intervention trial available to other researchers. Aggregate data are unlikely to present an opportunity for secondary analysis or subsequent publication, though they can provide more detail than may be available in a peer-reviewed publication.