Department of General Internal Medicine and Psychosomatics, Medical University of Heidelberg, Heidelberg, Germany.
Int J Eat Disord. 2013 Jul;46(5):425-32. doi: 10.1002/eat.22099.
Eating disorders are serious psychosomatic disorders with high morbidity and lifetime mortality. Inadequate response to current therapeutic interventions constitutes a challenging clinical problem. A better understanding of the underlying neurobiological mechanisms could improve psychotherapeutic and drug treatment strategies.
A review highlighting the current state of brain imaging in eating disorders related to the anxiety and pathological fear learning model of anorexia nervosa (AN) and the impulsivity model of binge eating in bulimia nervosa (BN).
Available neuroimaging studies in patients with acute AN primarily suggest a hyper-responsive emotional and fear network to food, but not necessarily to eating disorder-unrelated, salient stimuli. Furthermore, patients with AN show decreased activation in the ventral fronto-striatal circuits during the performance of a cognitive flexibility task. Results in patients with BN primarily suggest a hypo-responsive reward system to food stimuli, especially to taste reward. Additionally, patients with BN exhibit impaired brain activation in the inhibitory control network during the performance of general response-inhibition tasks.
Anxiety and pathological fear learning may lead to conditioned neural stimulus-response patterns to food stimuli and increased cognitive rigidity, which could account for the phobic avoidance of food intake in patients with acute AN. However, further neurobiological studies are required to investigate pathological fear learning in patients with AN. Patients with BN may binge eat to compensate for a hypo-responsive reward system. The impaired brain activation in the inhibitory control network may facilitate the loss of control over food intake in patients with BN.
饮食失调是一种严重的身心障碍，发病率和终生死亡率都很高。目前治疗干预的反应不足是一个具有挑战性的临床问题。更好地了解潜在的神经生物学机制可以改善心理治疗和药物治疗策略。
本文回顾了与神经性厌食症（AN）的焦虑和病理性恐惧学习模型以及贪食症（BN）的冲动模型相关的饮食失调的脑成像的最新研究进展。
急性 AN 患者的神经影像学研究主要表明，他们的情绪和恐惧网络对食物的反应过度，但对与饮食失调无关的显著刺激不一定反应过度。此外，AN 患者在执行认知灵活性任务时，腹侧额纹状体回路的激活减少。BN 患者的研究结果主要表明，他们的奖励系统对食物刺激反应不足，尤其是对味觉奖励的反应不足。此外，BN 患者在执行一般反应抑制任务时，抑制控制网络的大脑激活受损。
焦虑和病理性恐惧学习可能导致对食物刺激的条件性神经刺激-反应模式和认知僵化增加，这可以解释急性 AN 患者对食物摄入的恐惧回避。然而，还需要进一步的神经生物学研究来探讨 AN 患者的病理性恐惧学习。BN 患者可能会通过暴食来补偿反应不足的奖励系统。抑制控制网络的大脑激活受损可能会促进 BN 患者对食物摄入失去控制。
