“…Twenty-two studies reported drug use/abstinence as an MOUD outcome. Ten were experimental [65,66,67,68,69,70,71,59,60,72] and 12 were observational [34,33,55,35,36,37,56,38,39,40,41,32]. Sixteen studies indicated that social network support was related with reduced drug use/abstinence [67,68,69,33,55,35,36,72,37,41,56,70,59,38,71,39].…”