Külz Anne Katrin, Meinzer Sandra, Kopasz Marta, Voderholzer Ulrich
Department of Psychiatry and Psychotherapy, University Hospital of Freiburg, Freiburg, Germany.
Neuropsychobiology. 2007;56(2-3):127-31. doi: 10.1159/000115778. Epub 2008 Feb 7.
Previous studies suggest that obsessive-compulsive disorder (OCD) is associated with moderate cognitive deficits. There is also evidence for altered serotonergic transmission in OCD. The aim of this study was to evaluate the impact of rapid plasma tryptophan depletion on cognitive functioning in OCD.
A double-blind crossover study was conducted to explore the effects of tryptophan depletion on cognitive functioning, obsessive or compulsive (OC) symptoms and mood in OCD patients treated with selective serotonin reuptake inhibitors.
After 5 h of tryptophan depletion, 6 out of 7 patients reported worsening of mood (placebo condition: 3 patients). No effect was found regarding OC symptoms. There was a small and nonsignificant improvement of nonverbal memory and fluency. Problem solving ability and verbal memory, in contrast, were slightly impaired after tryptophan depletion. The results, however, represented only tendencies without reaching significance.
The results suggest that OC symptoms may not depend on the short-time availability of serotonin. As some critical cognitive functions improved following tryptophan depletion, there is no evidence from our study that neuropsychological impairment in OCD can be reduced to a lowered level of serotonin. Future studies are needed to further clarify these findings by use of larger samples.
先前的研究表明，强迫症（OCD）与中度认知缺陷有关。也有证据表明强迫症患者的血清素能传递发生了改变。本研究的目的是评估快速血浆色氨酸耗竭对强迫症患者认知功能的影响。
进行了一项双盲交叉研究，以探讨色氨酸耗竭对接受选择性5-羟色胺再摄取抑制剂治疗的强迫症患者的认知功能、强迫或强迫（OC）症状及情绪的影响。
色氨酸耗竭5小时后，7名患者中有6名报告情绪恶化（安慰剂组：3名患者）。未发现对OC症状有影响。非语言记忆和流畅性有小幅且无统计学意义的改善。相比之下，色氨酸耗竭后解决问题的能力和语言记忆略有受损。然而，这些结果仅显示出趋势，未达到统计学意义。
结果表明，OC症状可能不依赖于血清素的短期可用性。由于色氨酸耗竭后一些关键认知功能有所改善，我们的研究没有证据表明强迫症中的神经心理损害可归因于血清素水平降低。未来需要通过使用更大样本进一步阐明这些发现。
