Sherman 2009.

Study characteristics
Methods	Study design: RCT Duration of study: the study was conducted between 2005 (start of recruitment) and 2009 (publication). Country: Chiang Mai, Thailand Income classification: low‐middle‐income country from 2005 to 2009 Geographical scope: urban Healthcare setting: in the community, done in an ‘unmarked building’, which was a drug treatment centre
Participants	1. Age: 18 to 25 years old 2. Gender: both 3. Socioeconomic background: about one‐third worked, one‐third students, one‐third unemployed; primarily Buddhist (97.1%) and ethnically Thai (99.2%). A majority (63.8%) reported living with their parents. 4. Educational background: participants' education level was low, with only 39% reporting being currently in school and a median of 9 (interquartile range: 9‐11) years of schooling. Inclusion criteria: a. between the ages of 18 and 25 at screening; b. used methamphetamine at least three times; c. had sex at least three times in the past 3 months; d. were able to enrol at least one of their sex or drug network members in the study within 45 days of screening. Exclusion criteria: a. if they refused to have blood drawn or provide urine; b. if they were enrolled in another prevention study; c. if they refused to provide locator information. Note: at baseline, the intervention and control group scores for Center for Epidemiologic Studies Depression Scale (CES‐D) were, respectively, 20.0 (9.7) and 18.3 (9.1). Stated purpose: to examine the effects of a peer network intervention and a life skills intervention on methamphetamine and HIV risk behaviours amongst 18‐ to 25‐year‐olds
Interventions	Name: peer education condition Title/name of PW and number: peer educators (6) 1. Selection: 2 facilitators with 1 back‐up who were in their early 20s and had been a part of the ethnography team in the study's first phase 2. Educational background: not specified 3. Training: intensive 1‐week‐long training session, implemented using a manual. Facilitators were trained by the study's first and third authors. 4. Supervision: not specified 5. Incentives/remuneration: not specified Prevention type: indicated – participants presented with some level of distress as indicated by the CES‐D scores. Intervention details: seven 2‐hour sessions for each group undertaken by the facilitators over 1 month with twice‐weekly sessions. Participants in the peer education condition also attended 2 booster sessions that occurred 3 and 6 months after study entry. The aim was to teach participants to think critically about and reduce their methamphetamine use and sexual risk behaviours. Participants were taught communication skills that they practiced in role‐plays during the sessions and used to convey methamphetamine and risk reduction messages to specific social network members that were identified through a social network inventory administered at baseline. Sessions comprised interactive teaching modules, instructive games, and problem‐solving activities. Sessions ended with assigning peer education homework in which participants would discuss a specific issue with specific peers (MA‐using and/or sexual partners), which were reviewed at the beginning of the next session. Control: usual care – a life‐skills building approach based on a skills‐building approach that was largely derived from cognitive behavioural psychology, which is widely used with youth in drug treatment and juvenile justice settings in Thailand. The sessions focused on the causes and consequences of methamphetamine use at the individual level, with specific attention to stress in the role of drug use.
Outcomes	Participants’outcomes of interest for this review Depressive symptoms – CES‐D Carers’ outcomes of interest for this review Nil Economic outcomes Nil Time points: baseline, post‐intervention (7‐24 months)
Notes	Source of funding: not available Notes on validation of instruments (screening and outcomes): authors reported that the CES‐D had been validated among Thai adolescents. Additional information: none Handling the data: not available Prospective trial registration number: not available