Department of Psychiatry, University of California San Diego, San Diego, California, USA.
J Stud Alcohol Drugs. 2012 Sep;73(5):749-60. doi: 10.15288/jsad.2012.73.749.
Many adolescents engage in heavy alcohol use. The aim of this study was to disentangle whether brain abnormalities seen in adolescent heavy drinkers are a consequence of heavy drinking, a preexisting risk factor for initiation of alcohol use, or both.
Study 1 used cross-sectional functional magnetic resonance imaging (fMRI) visual working-memory (VWM) data from 15- to 19-year-olds (20 heavy drinkers, 20 controls) to identify brain regions affected by heavy adolescent alcohol use. Study 2 used longitudinal fMRI VWM data from 12- to 16-year-olds imaged before the onset of drinking and imaged again on the same scanner approximately 3 years later. Those who had transitioned into heavy drinking (n = 20) were matched to continuous nondrinkers (n = 20) on baseline alcohol risk and developmental factors (N = 40; 80 scans).
Study 1 found that heavy drinkers exhibited more frontal and parietal but less occipital activation than controls, defining the regions of interest for Study 2. In Study 2, adolescents who later transitioned into heavy drinking showed less fMRI response contrast at baseline than continuous nondrinkers, which increased after the onset of heavy drinking, in frontal (1,431 μL, p = .003; η² = .19) and parietal (810 μL, p = .005; η²= .23) regions, as in Study 1. Lower baseline activation in the frontal and parietal regions predicted subsequent substance use, more so than commonly observed predictors of youth drinking (p < .05).
Adolescents who initiated heavy drinking showed different brain activation before the onset of drinking, then less efficient information processing after high-dose alcohol use started. This suggests neural response patterns that could be risk factors for future substance use and also supports prior neuropsychological reports indicating that initiating heavy episodic drinking in adolescence may be followed by subtle alterations in brain functioning.
许多青少年酗酒。本研究旨在厘清青少年重度饮酒者大脑异常是饮酒的结果、饮酒开始的先前风险因素，还是两者兼而有之。
研究 1 使用来自 15 至 19 岁青少年（20 名重度饮酒者，20 名对照组）的横断面功能磁共振成像（fMRI）视觉工作记忆（VWM）数据，以确定受青少年重度饮酒影响的大脑区域。研究 2 使用来自 12 至 16 岁青少年的纵向 fMRI VWM 数据，这些青少年在饮酒前接受扫描，并在大约 3 年后在同一扫描仪上再次接受扫描。那些过渡到重度饮酒的人（n = 20）与基线酒精风险和发育因素相匹配的连续不饮酒者（n = 20）（n = 40；80 次扫描）。
研究 1 发现，与对照组相比，重度饮酒者的额叶和顶叶区域激活更多，而枕叶区域激活更少，从而确定了研究 2 的感兴趣区域。在研究 2 中，与连续不饮酒者相比，后来过渡到重度饮酒的青少年在基线时的 fMRI 反应对比较低，在额叶（1431 μL，p =.003；η² =.19）和顶叶（810 μL，p =.005；η²=.23）区域，这种情况在研究 1 中也存在。额叶和顶叶区域的基线激活较低，预测随后的物质使用，比青少年饮酒的常见预测指标更能预测（p <.05）。
开始重度饮酒的青少年在开始饮酒前显示出不同的大脑激活，然后在开始高剂量饮酒后信息处理效率降低。这表明神经反应模式可能是未来物质使用的风险因素，也支持先前的神经心理学报告，表明青少年开始重度间歇性饮酒可能会导致大脑功能的微妙改变。
