Supplementary Material for: Effects of Substance Misuse and Family History of Substance Use Disorder on Delay Discounting in Adolescents and Young Adults with Attention-Deficit/Hyperactivity Disorder

<b><i>Background:</i></b> Attention-deficit/hyperactivity disorder (ADHD) and substance use disorder (SUD) often co-occur. Both disorders are characterized by impulsive choice. However, little is known about the effects of substance misuse (SM) and family history of SUD (FH) on impulsive choice in ADHD-SUD comorbidity. Impulsive choice is also linked to callous-unemotional (CU) traits, which are suggested to play a role in ADHD-SUD comorbidity. Our aim was to examine the effects of (1) FH and (2) SM on impulsive choice, while exploring the role of CU traits. <b><i>Methods:</i></b> Impulsive choice was assessed with the delay discounting (DD) task. We compared task performance across (1) ADHD patients and controls with or without FH of SUD (ADHD FH+: <i>n</i> = 86; ADHD FH−: <i>n</i> = 63; control FH+: <i>n</i> = 49; control FH−: <i>n</i> = 72; mean age of the whole sample [<i>n</i> = 270]: 16.39, SD: 3.43) and (2) family history-matched ADHD groups with and without SM and controls (ADHD + SM: <i>n</i> = 62; ADHD-only: <i>n</i> = 62; controls: <i>n</i> = 62; mean age of the whole sample [<i>n</i> = 186]: 18.01, SD: 2.71). Effects of CU traits were explored by adding this as a covariate in all analyses. <b><i>Results:</i></b> (1) There was no main effect of FH on DD. (2) We found increased DD in ADHD + SM compared to ADHD-only and no difference between ADHD-only and controls. Finally, increased DD was associated with increased callous traits only in ADHD FH+ and control FH+. <b><i>Conclusions:</i></b> In adolescents and young adults with ADHD, high impulsive choice might only be present in those with comorbid SM and in an FH+ subgroup with high callous traits. This suggests that impulsive choice in ADHD might result from (1) effects of SM and (2) a combined effect of SUD vulnerability and high callousness. Future studies should investigate efficacy of early interventions, targeting CU traits.

<b><i>背景：</i></b> 注意缺陷多动障碍（ADHD）与物质使用障碍（SUD）常共病发生，两类障碍均以冲动性选择为核心特征。然而，目前对于物质滥用（SM）与物质使用障碍家族史（FH）对ADHD-SUD共病患者冲动性选择的影响仍知之甚少。此外，冲动性选择还与冷酷无情特质（CU）相关，后者被认为在ADHD-SUD共病中发挥一定作用。本研究旨在考察（1）物质使用障碍家族史（FH）与（2）物质滥用（SM）对冲动性选择的影响，并同时探讨冷酷无情特质（CU）所扮演的角色。<b><i>方法：</i></b> 本研究采用延迟折扣（DD）任务评估冲动性选择。我们开展了两项对比分析：（1）按是否存在物质使用障碍家族史（FH）分组，对比ADHD患者与健康对照的任务表现（ADHD FH+组：n=86；ADHD FH-组：n=63；对照FH+组：n=49；对照FH-组：n=72；全部样本共270例，平均年龄16.39岁，标准差SD=3.43）；（2）按家族史匹配，对比伴/不伴物质滥用（SM）的ADHD组与健康对照的任务表现（ADHD+SM组：n=62；单纯ADHD组：n=62；健康对照组：n=62；该亚组样本共186例，平均年龄18.01岁，SD=2.71）。所有分析均将冷酷无情特质（CU）作为协变量纳入，以探讨其效应。<b><i>结果：</i></b> （1）物质使用障碍家族史（FH）对延迟折扣（DD）无显著主效应。（2）与单纯ADHD组相比，ADHD+SM组的延迟折扣（DD）水平显著升高，而单纯ADHD组与健康对照组之间无显著差异。最后，仅在ADHD FH+组与对照FH+组中，延迟折扣（DD）水平升高与冷酷无情特质得分升高呈显著正相关。<b><i>结论：</i></b> 本研究结果表明，在ADHD青少年与年轻成人群体中，高冲动性选择仅见于伴发物质滥用（SM）的患者，以及具有高冷酷无情特质（CU）的FH+亚组人群。这提示ADHD患者的冲动性选择可能源于两方面因素：（1）物质滥用（SM）的直接影响；（2）物质使用障碍（SUD）易感性与高冷酷无情特质的联合作用。未来研究应探索针对冷酷无情特质（CU）的早期干预措施的有效性。