Brooks Samantha J
UCT Department of Psychiatry and Mental Health, Groote Schuur Hospital, Anzio Road, Observatory Cape Town, South Africa.
BMC Psychiatry. 2016 Jan 16;16:10. doi: 10.1186/s12888-016-0714-z.
Anorexia Nervosa (AN) is a debilitating, sometimes fatal eating disorder (ED) whereby restraint of appetite and emotion is concomitant with an inflexible, attention-to-detail perfectionist cognitive style and obsessive-compulsive behaviour. Intriguingly, people with AN are less likely to engage in substance use, whereas those who suffer from an ED with a bingeing component are more vulnerable to substance use disorder (SUD).
This insight into a beneficial consequence of appetite control in those with AN, which is shrouded by the many other unhealthy, excessive and deficit symptoms, may provide some clues as to how the brain could be trained to exert better, sustained control over appetitive and impulsive processes. Structural and functional brain imaging studies implicate the executive control network (ECN) and the salience network (SN) in the neuropathology of AN and SUD. Additionally, excessive employment of working memory (WM), alongside more prominent cognitive deficits may be utilised to cope with the experience of negative emotions and may account for aberrant brain function. WM enables mental rehearsal of cognitive strategies while regulating, restricting or avoiding neural responses associated with the SN. Therefore, high versus low WM capacity may be one of the factors that unites common cognitive and behavioural symptoms in those suffering from AN and SUD respectively. Furthermore, emerging evidence suggests that by evoking neural plasticity in the ECN and SN with WM training, improvements in neurocognitive function and cognitive control can be achieved. Thus, considering the neurocognitive processes of excessive appetite control and how it links to WM in AN may aid the application of adjunctive treatment for SUD.
神经性厌食症(AN)是一种使人衰弱、有时甚至致命的饮食失调症(ED),食欲和情绪的抑制与僵化、注重细节的完美主义认知风格及强迫行为相伴。有趣的是,患有神经性厌食症的人较少使用药物,而那些患有伴有暴饮暴食成分的饮食失调症的人更容易患上物质使用障碍(SUD)。
对神经性厌食症患者食欲控制的有益后果的这一见解,被许多其他不健康、过度和不足的症状所掩盖,这可能为如何训练大脑对食欲和冲动过程施加更好、更持久的控制提供一些线索。大脑结构和功能成像研究表明,执行控制网络(ECN)和突显网络(SN)与神经性厌食症和物质使用障碍的神经病理学有关。此外,工作记忆(WM)的过度使用,以及更明显的认知缺陷,可能被用来应对负面情绪体验,并可能导致大脑功能异常。工作记忆在调节、限制或避免与突显网络相关的神经反应时,能够对认知策略进行心理预演。因此,高工作记忆能力与低工作记忆能力可能分别是导致神经性厌食症和物质使用障碍患者出现共同认知和行为症状的因素之一。此外,新出现的证据表明,通过工作记忆训练激发执行控制网络和突显网络中的神经可塑性,可以实现神经认知功能和认知控制的改善。因此,考虑过度食欲控制的神经认知过程及其在神经性厌食症中与工作记忆的联系,可能有助于物质使用障碍辅助治疗的应用。