This study evaluated how individuals’ own substance use and their perception of peers’ substance use predict each other across development from early adolescence to middle adulthood. Participants were from two longitudinal studies: Fast Track (FT; N = 463) and Child Development Project (CDP; N = 585). Participants reported on their own and peers’ substance use during early and middle adolescence and early adulthood, and their own substance use in middle adulthood. From adolescence to early adulthood, individuals’ reports of their own substance use in a given developmental period predicted reports of their peers’ substance use in the next developmental period more than peers’ substance use in a given developmental period predicted individuals’ own substance use in the next. In the higher-risk FT sample, individuals’ own substance use in early adulthood predicted alcohol, cannabis, and other substance use in middle adulthood, and peers’ substance use in early adulthood predicted cannabis use in middle adulthood. In the lower-risk CDP sample, participants’ own substance use in early adulthood predicted only their own cannabis use in middle adulthood, whereas peers’ substance use in early adulthood predicted participants’ alcohol, cannabis, opioid, and other substance use in middle adulthood. The findings suggest that peer substance use in early adulthood may indicate a greater propensity for subsequent substance use in lower-risk groups, whereas those in higher-risk groups may remain more stable in substance use, with less variability explained by peer contexts.

这项研究评估了个人自己的物质使用情况和他们对同伴物质使用情况的看法如何在从青春期早期到成年中期的整个发展过程中相互预测。参与者来自两项纵向研究：快速通道（FT；N  = 463）和儿童发展项目（CDP；N = 585)。参与者报告了他们自己和同龄人在青春期早期和中期以及成年早期的物质使用情况，以及他们自己在成年中期的物质使用情况。从青春期到成年早期，个人在给定发展时期对自己物质使用的报告预测其同伴在下一个发展时期的物质使用报告比同龄人在给定发展时期的物质使用预测个人在给定发展时期的物质使用更多下一个。在风险较高的 FT 样本中，个人在成年早期的自身物质使用预测了成年中期的酒精、大麻和其他物质使用，而同龄人在成年早期的物质使用预测了成年中期的大麻使用。在风险较低的 CDP 样本中，参与者自己在成年早期的物质使用仅预测了他们自己在成年中期的大麻使用，而同龄人在成年早期的物质使用预测了参与者在成年中期的酒精、大麻、阿片类药物和其他物质的使用。研究结果表明，成年早期的同伴物质使用可能表明低风险人群后续物质使用的倾向更大，而高风险人群的物质使用可能保持更稳定，同伴环境解释的变异性较小。