注意力不集中？原来这是一种大脑的疾病

Certain brain structures related to emotion and reward are smaller in people with the disorder, new research finds.

据最新的研究表明,患有多动症的人的大脑中与情感和奖励有关的组成结构比常人更小。

The largest-ever brain imaging study on attention deficit hyperactivity disorder has led scientists to say the condition should be considered a neurological disorder, not just a behavioral one.

有史以来,对多动症最深入的脑成像研究让科学家发现,这应该是一种神经系统疾病,而不仅仅是一种行为。

The brain structures of children with ADHD differ in small but significant ways from those of normally developing children, according to the findings, which were published online in the journal Lancet Psychiatry on Feb. 15.

2月15日,发表在柳叶刀医学杂志上的研究结果显示,患有多动症儿童的大脑结构比正常发育的儿童更小,但也更能发挥效用。

Up to 11 percent of U.S. children and around 5 percent of U.S. adults have been diagnosed with ADHD, which causes symptoms like difficulty paying attention, impulsivity, irritability and forgetfulness.

高达百分之11的美国孩子以及百分之5左右的美国成人被诊断患有多动症,这导致了他们产生注意力难以集中、冲动、烦躁、健忘等症状。

The study’s authors hope that the research will help to combat widespread misunderstanding of ADHD, which is often seen as some sort of motivational deficit or character failing rather than a real disorder. The findings show that the disorder is as real as other neuropsychiatric disorders like depression or obsessive-compulsive disorder.

该项研究的作者希望这能够帮助解决大众对多动症的普遍误解,因为往往大家会认为这是种动机或性格缺陷而不是一种疾病。但研究结果表明,多动症和抑郁症以及强迫症一样都属于神经性精神疾病。

For the study, a team of Dutch neuroscientists analyzed MRI scans of the brains of more than 3,200 people between the ages of four and 63 years old (with a median age of 14 years old), measuring total brain volume as well as the volume of seven brain regions thought to be linked to ADHD. Roughly half of the participants had a diagnosis of ADHD.

在这项研究中,一批荷兰科学家分析了年龄在4到63岁之间(平均年龄14岁)的3200多人的大脑核磁共振扫描结果,测量了大脑总体积以及大脑七块与多动症的产生相关的区域体积。大约一半的参与者被诊断出患有多动症。

The brain scans revealed that five brain regions were smaller in people with ADHD. These include the amygdala, an almond-shaped structure involved in processing emotions like fear and pleasure; the hippocampus, which plays a role in learning, memory and emotion; and three brain areas within the striatum ― the caudate nucleus, the putamen and the nucleus accumbens. The structures within the striatum are involved in the brain’s reward system and in its processing of dopamine, a neurotransmitter that helps control motivation and pleasure.

脑部扫描结果显示,患有多动症的人的五个大脑区域较小。其中包括杏仁核,一种处理类似恐惧和愉悦的情感的杏仁状结构;海马在学习、记忆和情感中发挥作用;另外在纹状体中还有三个大脑区域---纹状体尾状核、壳核和伏隔核。在纹状体中的这些结构是大脑的奖励系统中的一部分,在它处理多巴胺的过程中,有一种神经递质能控制动机和情绪。

These differences were more dramatic in children than in adults, leading the study’s authors to conclude that ADHD involves delayed brain development. It appears that as the brains of people with ADHD develop and mature, these brain regions “catch up” to the brain regions of people without ADHD.

这些差异在儿童身上比成人显现得更具戏剧性,根据这项研究的作者得出的结论表明:患有多动症的人大脑发育较为迟缓。但当有多动症的人的大脑发育并逐渐成熟时,这些大脑区域的发展会“赶超”没有多动症的人。

At the time of the study, 455 of the participants with ADHD were taking psychostimulant medication like Adderall, and more than 600 others had taken psychostimulants in the past but were not currently on medication. Brain volume differences did not correlate with stimulant use, suggesting that such discrepancies were not a result of medication.

在研究期间,455名多动症患者服用了兴奋剂药物如Adderall,超过600人在以前服用过兴奋剂但现在未服药。脑容量的差异与使用兴奋剂并无关系,这表明这种差异并不是由于药物引起的。

“We only studied a small part of the brain,” Hoogman said. “There is still a long way to go.”

“我们只研究了大脑的一小部分,”Hoogman说。“要真正了解大脑、研究多动症,还有很长的路要走。”