Cannabis use in adolescence may be characterized by differences in the neural basis of affective processing. In this study, we used an fMRI affective face processing task to compare a large group (n = 70) of 14-year olds with a history of cannabis use to a group (n = 70) of never-using controls matched on numerous characteristics including IQ, SES, alcohol and cigarette use. The task contained short movies displaying angry and neutral faces. Results indicated that cannabis users had greater reactivity in the bilateral amygdalae to angry faces than neutral faces, an effect that was not observed in their abstinent peers. In contrast, activity levels in the cannabis users in cortical areas including the right temporal-parietal junction and bilateral dorsolateral prefrontal cortex did not discriminate between the two face conditions, but did differ in controls. Results did not change after excluding subjects with any psychiatric symptomology. Given the high density of cannabinoid receptors in the amygdala, our findings suggest cannabis use in early adolescence is associated with hypersensitivity to signals of threat. Hypersensitivity to negative affect in adolescence may place the subject at-risk for mood disorders in adulthood.

青春期使用大麻的特点可能是情感处理的神经基础存在差异。在这项研究中，我们使用 fMRI 情感面部处理任务来比较一大组（n  = 70）有大麻使用史的 14 岁儿童与一组（n = 70) 从未使用过的对照与许多特征相匹配，包括智商、社会经济地位、酒精和香烟使用。该任务包含展示愤怒和中性面孔的短片。结果表明，与中性面孔相比，大麻使用者的双侧杏仁核对愤怒面孔的反应更大，这种效应在他们禁欲的同龄人中没有观察到。相比之下，包括右侧颞顶叶交界处和双侧背外侧前额叶皮层在内的皮层区域的大麻使用者的活动水平并没有区分两种面部状况，但在对照组中确实存在差异。排除具有任何精神症状的受试者后，结果没有改变。鉴于杏仁核中大麻素受体的高密度，我们的研究结果表明，在青春期早期使用大麻与对威胁信号的超敏反应有关。对青春期负面影响的超敏反应可能会使受试者在成年期面临情绪障碍的风险。