Data from: Dissociable temporal effects of bupropion on behavioural measures of emotional and reward processing in depression

Background: Antidepressants remediate negative biases in emotional processing early in treatment, prior to mood improvement. However, the effects on reward processing potentially relevant to the treatment of anhedonia are less clear. Here we investigate the early and sustained effects of the dopamine and noradrenaline reuptake inhibitor bupropion on behavioural measures of emotional and reward processing in currently depressed individuals. Methods: 46 currently depressed patients and 42 healthy controls participated in a repeated measures study, during which open-label bupropion was administered to only the patient group over a 6 week period without a placebo group. All participants completed the Emotional Test Battery and a probabilistic instrumental learning task at week 0, week 2 and week 6. Results: Currently depressed patients displayed negative biases in emotional processing and blunted response bias for high-probability wins compared to the healthy controls at baseline. Bupropion was found to reduce the negative biases in emotional processing early in treatment, including a significant decrease in the percentage misclassification of other face emotions as sad and the number of negative self-referent words falsely recalled between baseline and week 2. Conversely, bupropion was found to initially further reduce the response bias for high-probability wins between baseline and week 2. This effect reversed with 6 weeks bupropion treatment and reward processing was normalised compared to the healthy controls. Conclusions: Early in treatment, bupropion acts to reduce negative biases in emotional processing but exacerbates impaired reward processing. The beneficial actions of bupropion on reward processing then occur later in treatment. Such dissociation in the temporal effects of bupropion on emotional and reward processing has implications for the treatment of the different symptom domains of negative affect and anhedonia in depression.研究背景：抗抑郁药可在治疗早期、情绪改善前纠正情绪加工中的负性偏差。然而，其对与快感缺失（anhedonia）治疗相关的奖赏加工的影响尚不明确。本研究旨在探讨多巴胺和去甲肾上腺素再摄取抑制剂（dopamine and noradrenaline reuptake inhibitor）安非他酮（bupropion）对当前抑郁个体情绪加工与奖赏加工行为学指标的早期及持续影响。 研究方法：46名当前抑郁患者与42名健康对照参与本重复测量研究，仅患者组在6周周期内接受开放标签安非他酮治疗，未设置安慰剂组。所有受试者分别在第0周、第2周及第6周完成情绪测试电池（Emotional Test Battery）与概率性工具性学习任务（probabilistic instrumental learning task）。 研究结果：基线时，相较于健康对照，当前抑郁患者表现出情绪加工的负性偏差，且对高概率奖赏获益的反应偏差出现钝化。安非他酮可在治疗早期降低情绪加工的负性偏差，具体表现为：在基线至第2周期间，将其他面部情绪误分类为悲伤情绪的比例显著下降，且错误回忆的负性自我参照词汇数量显著减少。与之相反，安非他酮在基线至第2周期间最初会进一步降低高概率奖赏获益的反应偏差。该效应在6周安非他酮治疗后发生逆转，奖赏加工水平恢复至与健康对照相当的正常状态。 研究结论：治疗早期，安非他酮可降低情绪加工的负性偏差，但会加重奖赏加工的受损程度；其对奖赏加工的有益作用则在治疗后期显现。安非他酮在情绪加工与奖赏加工上的这种时间效应解离，可为抑郁症中负性情感与快感缺失这两类不同症状维度的治疗提供参考依据。