The authors sought evidence for altered adolescent brain growth trajectory associated with moderate and heavy alcohol use in a large national, multisite, prospective study of adolescents before and after initiation of appreciable alcohol use.

This study examined 483 adolescents (ages 12–21) before initiation of drinking and 1 and 2 years later. At the 2-year assessment, 356 participants continued to meet the study’s no/low alcohol consumption entry criteria, 65 had initiated moderate drinking, and 62 had initiated heavy drinking. MRI was used to quantify regional cortical and white matter volumes. Percent change per year (slopes) in adolescents who continued to meet no/low criteria served as developmental control trajectories against which to compare those who initiated moderate or heavy drinking.

In no/low drinkers, gray matter volume declined throughout adolescence and slowed in many regions in later adolescence. Complementing gray matter declines, white matter regions grew at faster rates at younger ages and slowed toward young adulthood. Youths who initiated heavy drinking exhibited an accelerated frontal cortical gray matter trajectory, divergent from the norm. Although significant effects on trajectories were not observed in moderate drinkers, their intermediate position between no/low and heavy drinkers suggests a dose effect. Neither marijuana co-use nor baseline volumes contributed significantly to the alcohol effect.

Initiation of drinking during adolescence, with or without marijuana co-use, disordered normal brain growth trajectories. Factors possibly contributing to abnormal cortical volume trajectories include peak consumption in the past year and family history of alcoholism.

作者在大量的全国性，多场所，前瞻性研究中，对开始大量饮酒前后的青少年，研究了与适度和重度饮酒有关的青少年大脑生长轨迹改变的证据。

这项研究检查了483名青少年（12至21岁）在开始饮酒之前以及1和2年后的情况。在为期2年的评估中，有356名参与者继续达到了研究的无/低酒精摄入量输入标准，其中65名开始中度饮酒，62人开始大量饮酒。MRI用于量化区域皮层和白质体积。继续达到无/低标准的青少年每年的百分比变化（斜率）作为发展控制轨迹，可以用来与那些开始中度或重度饮酒的人进行比较。

在无/低饮酒者中，整个青春期的灰质量下降，而在青春期后的许多地区则减慢。为弥补灰质的下降，白质地区在年轻时以更快的速度增长，而在成年后则有所放缓。开始大量饮酒的年轻人表现出加速的额叶皮层灰质运动，这与正常情况背道而驰。尽管在中度饮酒者中未观察到对轨迹的显着影响，但在非饮酒者/低饮者和重度饮酒者之间的中间位置提示了剂量效应。大麻的共同使用和基线量都没有显着影响酒精的影响。

在青春期开始饮酒时，有或没有大麻共同使用，正常的大脑生长轨迹就会紊乱。可能导致皮质容积异常的因素包括过去一年的高峰食用量和酗酒家族史。