Poulton Antoinette, Gauci Natalie, Khalifa Hazer, Hibbert Emily J, Poulton Alison S
Melbourne School of Psychological Sciences, University of Melbourne, Parkville, VIC 3052, Australia.
Nepean Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2751, Australia.
Brain Sci. 2024 Dec 18;14(12):1274. doi: 10.3390/brainsci14121274.
Amphetamines increase dopamine levels in mid-brain regions which, in turn, impact top-down executive function. Repeated exposure is linked to substance use disorders. Nonetheless, amphetamines are used to manage attention-deficit/hyperactivity disorder (ADHD) and eating-related disorders. In ADHD, amphetamines upregulate a system characterised by low dopaminergic tone, assisting to improve executive function. A similar process might be at play with eating disorders; however, the effect of amphetamine treatment on executive function in this case has not been thoroughly considered.
Participants ( = 52, = 47.06, = 12.29) with a body mass index of 25-60 were randomised to treatment (6-week dexamphetamine titration) or control (placebo) groups. They completed an executive function measure-Barkley Deficits in Executive Functioning Scale (BDEFS-SF)-and response inhibition task-Stop-Signal Task (SST)-at Baseline, throughout titration, at Maintenance, and at Follow-up. Mixed effects models examined whether BDEFS-SF score or the SST variable, stop-signal reaction time (SSRT), changed across sessions as a function of treatment.
There was no effect of group ( = 0.440), but an effect of session ( = 0.024) on BDEFS-SF, with scores at Time 2 ( = 0.011, 95% CI [0.47, 3.49]) and Maintenance ( = 0.022, 95% CI [-4.89, -0.39]), respectively, higher and lower than other timepoints. There was no group by session interaction ( = 0.659). (conditional) = 0.74; ICC = 0.73. There was an effect of group ( = 0.039) and session ( < 0.001) on SSRT, but no interaction ( = 0.707). Baseline SSRT was significantly longer than the mean of all subsequent timepoints ( < 0.001, 95% CI [16.29, 33.84]). (conditional) = 0.47; ICC = 0.39.
There was no discernible impact of amphetamine treatment for obesity on executive function. Our results suggest some variation related to sample size and/or practice effects. Thus, while treatment appears unlikely to render individuals susceptible to substance use disorders, parallels with ADHD might be overstated.
安非他命会提高中脑区域的多巴胺水平，进而影响自上而下的执行功能。反复接触与物质使用障碍有关。尽管如此，安非他命仍被用于治疗注意力缺陷多动障碍（ADHD）和饮食相关障碍。在ADHD中，安非他命会上调一个以多巴胺能张力低为特征的系统，有助于改善执行功能。类似的过程可能在饮食障碍中也起作用；然而，在这种情况下，安非他命治疗对执行功能的影响尚未得到充分考虑。
将体重指数为25至60的参与者（n = 52，M = 47.06，SD = 12.29）随机分为治疗组（6周右旋苯丙胺滴定）或对照组（安慰剂）。他们在基线、滴定全程、维持期和随访时完成了一项执行功能测量——巴克利执行功能缺陷量表（BDEFS-SF）和反应抑制任务——停止信号任务（SST）。混合效应模型检验了BDEFS-SF分数或SST变量，即停止信号反应时间（SSRT），是否随治疗而在各阶段发生变化。
组间效应不显著（p = 0.440），但阶段对BDEFS-SF有影响（p = 0.024），第2次（p = 0.011，95%置信区间[0.47，3.49]）和维持期（p = 0.022，95%置信区间[-4.89，-0.39]）的分数分别高于和低于其他时间点。组间与阶段无交互作用（p = 0.659）。个体内相关系数（条件）= 0.74；组内相关系数（ICC）= 0.73。组间（p = 0.039）和阶段（p < 0.001）对SSRT有影响，但无交互作用（p = 0.707）。基线SSRT显著长于所有后续时间点的平均值（p < 0.001，95%置信区间[16.29，33.84]）。个体内相关系数（条件）= 0.47；组内相关系数（ICC）= 0.39。
安非他命治疗肥胖对执行功能没有明显影响。我们的结果表明存在一些与样本量和/或练习效应相关的差异。因此，虽然治疗似乎不太可能使个体易患物质使用障碍，但与ADHD的相似性可能被夸大了。
