Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA.
Eat Weight Disord. 2021 Jun;26(5):1669-1674. doi: 10.1007/s40519-020-00970-z. Epub 2020 Aug 3.
Validation of transcranial direct current stimulation (tDCS) to treat obesity is hampered by evidence that participants can distinguish real from the traditional-control condition. Correctly guessing the real condition precludes knowing if it is neuromodulation or expectation that suppresses food craving and eating. Therefore, this study tested the putative efficacy of tDCS to the dorsolateral prefrontal cortex (DLPFC) to reduce food craving and eating when an alternative control condition was used that would be difficult to distinguish from the real condition.
N = 28 adults with a 26-50 BMI range received a typical 20-min 2 mA current session of tDCS targeting the DLPFC as the real condition and a same duration/current tDCS session targeting the sensorimotor cortex (SMC), a region not expected to affect appetite, as the control. Food image craving ratings, in-lab food consumption, and momentary ratings of physical sensations were measured.
DLPFC failed to reduce food craving and consumption compared to SMC stimulation. When interviewed, 71% of participants were unable to guess real from control conditions. Those who guessed DLPFC tDCS as real attributed their guess to increased number and frequency of sensations. However, their sensation ratings during tDCS did not differ between conditions.
The results question if tDCS suppresses craving and eating at all, or if the DLPFC is the best target to do so. The results also indicate that alternate-site constant stimulation as the control method may strengthen the scientific evaluation of tDCS to treat obesity.
Level I, experimental study.
经颅直流电刺激（tDCS）治疗肥胖的有效性受到限制，因为有证据表明参与者可以区分真实刺激和传统对照条件。正确猜测真实条件会让人无法知道抑制食欲和进食的原因是神经调节还是预期。因此，本研究测试了使用替代性对照条件（很难与真实条件区分）时，对背外侧前额叶皮层（DLPFC）进行 tDCS 是否能有效抑制食欲和进食。
n=28 名 BMI 为 26-50 的成年人接受了典型的 20 分钟 2 mA 电流刺激，DLPFC 为真实刺激，感觉运动皮层（SMC）为相同时长/电流刺激作为对照，SMC 区域预计不会影响食欲。测量了食物图片的渴望评分、实验室食物消耗量和即时的身体感觉评分。
与 SMC 刺激相比，DLPFC 并未降低食物渴望和消耗。当被询问时，71%的参与者无法从对照条件中猜测真实情况。那些猜测 DLPFC tDCS 为真实刺激的人将他们的猜测归因于感觉数量和频率的增加。然而，他们在 tDCS 期间的感觉评分在两种条件之间没有差异。
结果质疑 tDCS 是否真的能抑制食欲和进食，或者 DLPFC 是否是抑制食欲和进食的最佳目标。结果还表明，替代部位恒定刺激作为对照方法可能会增强 tDCS 治疗肥胖的科学评估。
一级，实验研究。
