Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health, University of Tübingen, Tübingen, Germany.
Section of Medical Psychology, Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Bonn, Bonn, Germany.
Compr Psychiatry. 2024 Jul;132:152488. doi: 10.1016/j.comppsych.2024.152488. Epub 2024 Apr 16.
Major depressive disorder (MDD) is often marked by impaired motivation and reward processing, known as anhedonia. Many patients do not respond to first-line treatments, and improvements in motivation can be slow, creating an urgent need for rapid interventions. Recently, we demonstrated that transcutaneous auricular vagus nerve stimulation (taVNS) acutely boosts effort invigoration in healthy participants, but its effects on depression remain unclear.
To assess the impact of taVNS on effort invigoration and maintenance in a sample that includes patients with MDD, evaluating the generalizability of our findings.
We used a single-blind, randomized crossover design in 30 patients with MDD and 29 matched (age, sex, and BMI) healthy control participants (HCP).
Consistent with prior findings, taVNS increased effort invigoration for rewards in both groups during Session 1 (p = .040), particularly for less wanted rewards in HCP (p < 0.001). However, invigoration remained elevated in all participants, and no acute changes were observed in Session 2 (Δinvigoration = 3.3, p = .12). Crucially, throughout Session 1, we found taVNS-induced increases in effort invigoration (p = 0.008) and wanting (p = 0.010) in patients with MDD, with gains in wanting maintained across sessions (Δwanting = 0.06, p = .97).
Our study replicates the invigorating effects of taVNS in Session 1 and reveals its generalizability to depression. Furthermore, we expand upon previous research by showing taVNS-induced conditioning effects on invigoration and wanting within Session 1 in patients that were largely sustained. While enduring motivational improvements present challenges for crossover designs, they are highly desirable in interventions and warrant further follow-up research.
重度抑郁症（MDD）常伴有动机和奖励加工受损，即快感缺失。许多患者对一线治疗无反应，且动机改善缓慢，这就迫切需要快速干预。最近，我们发现经皮耳迷走神经刺激（taVNS）可急性增强健康参与者的努力激励，但 taVNS 对抑郁症的影响仍不清楚。
在包括 MDD 患者在内的样本中评估 taVNS 对努力激励和维持的影响，评估我们发现的普遍性。
我们在 30 名 MDD 患者和 29 名匹配的（年龄、性别和 BMI）健康对照参与者（HCP）中使用单盲、随机交叉设计。
与之前的发现一致，在第 1 次会话中，taVNS 增加了两组的奖励努力激励（p=0.040），特别是在 HCP 中不太想要的奖励（p<0.001）。然而，所有参与者的激励仍然升高，在第 2 次会话中没有观察到急性变化（Δ激励=3.3，p=0.12）。至关重要的是，在整个第 1 次会话中，我们发现 taVNS 诱导的 MDD 患者努力激励（p=0.008）和欲望（p=0.010）增加，欲望的增加在整个会话中持续（Δ欲望=0.06，p=0.97）。
我们的研究复制了 taVNS 在第 1 次会话中的激励作用，并揭示了其在抑郁症中的普遍性。此外，我们通过显示 taVNS 在第 1 次会话中对激励和欲望的诱发调节作用，进一步扩展了之前的研究，这些作用在很大程度上得到了维持。虽然持久的动机改善对交叉设计提出了挑战，但它们在干预措施中是非常理想的，值得进一步的后续研究。
