Child Neurology, Pediatric Headache Centre, Sleep Disorders Centre, Chair of Pediatrics, NESMOS Department, Faculty of Medicine & Psychology, Sapienza University, Via di Grottarossa, 1035-1039, 00189 Rome, Italy.
Med Hypotheses. 2012 Aug;79(2):246-9. doi: 10.1016/j.mehy.2012.04.049. Epub 2012 May 25.
Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most common childhood-onset neuropsychiatric conditions. Despite extensive research, the etiopathophysiological factors underlying ADHD are not completely understood. It has been suggested that iron deficiency may contribute to ADHD symptoms severity. Whereas evidence from studies based on serum ferritin measures, a marker of peripheral iron status, is somewhat mixed, preliminary recent evidence suggests a deficiency of brain iron in individuals with ADHD. Therefore, it has been proposed that either a deficiency of peripheral iron or a dysfunction of the blood-brain barrier, in the presence of normal peripheral iron levels, may contribute to low brain iron levels, which, in turn, would increase the risk for ADHD symptoms in a subgroup of individuals with this disorder. It has also been found that individuals with ADHD may be at increased risk of severe cardiovascular events during treatment with ADHD drugs, although the extent to which this occurs in ADHD patients compared to non-ADHD individuals is still matter of investigation. Since iron depletion has been recently reported as a risk factor for adverse prognosis in heart failure, iron deficiency might contribute both to ADHD symptoms severity before treatment and to increased risk of severe cardiovascular events during treatment with ADHD drugs in a selected subgroup of patients. Therefore, we hypothesize that the effective treatment of iron deficiency might lead both to improvement of ADHD symptoms severity and to a decrease of the risk of cardiovascular events during treatment with ADHD drugs. If empirical studies confirm this hypothesis, the clinician would be advised to systematically check iron status and effectively treat iron deficiency before starting a pharmacological treatment with ADHD drugs.
注意缺陷多动障碍(ADHD)是最常见的儿童期神经精神疾病之一。尽管进行了广泛的研究,但 ADHD 的病因和发病机制仍不完全清楚。有研究表明,缺铁可能与 ADHD 症状的严重程度有关。虽然基于血清铁蛋白测量的研究证据(外周铁状态的标志物)有些混杂,但最近的初步证据表明,ADHD 患者存在脑铁缺乏。因此,有人提出,在正常外周铁水平的情况下,外周铁缺乏或血脑屏障功能障碍可能导致脑铁水平降低,这反过来又会增加患有这种疾病的亚组个体发生 ADHD 症状的风险。还有研究发现,ADHD 患者在接受 ADHD 药物治疗时发生严重心血管事件的风险可能增加,尽管与非 ADHD 患者相比,ADHD 患者发生这种情况的程度仍有待研究。由于铁耗竭最近被报道为心力衰竭不良预后的一个危险因素,因此缺铁可能会导致 ADHD 患者在接受治疗前症状严重,并在接受 ADHD 药物治疗期间发生严重心血管事件的风险增加。因此,我们假设有效的铁缺乏治疗可能会导致 ADHD 症状严重程度的改善,并降低接受 ADHD 药物治疗期间发生心血管事件的风险。如果实证研究证实了这一假设,临床医生将被建议在开始使用 ADHD 药物进行药物治疗之前,系统地检查铁状况并有效地治疗缺铁。