Images of PET scans showing normal brain activity (right) and reduced brain activity due to depression (left)

正电子发射断层成像(PET)扫描可以对比患抑郁症时的大脑活动(左侧)和正常的大脑活动(右侧)。蓝色和绿色增加,以及白色和黄色区域减少,显示出抑郁症导致的大脑活动减少。