Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, QC, H3A 1A1, Canada.
Obsessive Compulsive Disorder Clinic, Department of Psychology, McGill University Health Center, Montreal, QC, H3A 1A1, Canada.
Transl Psychiatry. 2018 Apr 18;8(1):82. doi: 10.1038/s41398-018-0128-4.
Cognitive behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) are both effective treatments for some patients with obsessive-compulsive disorder (OCD), yet little is known about the neurochemical changes related to these treatment modalities. Here, we used positron emission tomography and the α-[C]methyl-L-tryptophan tracer to examine the changes in brain regional serotonin synthesis capacity in OCD patients following treatment with CBT or SSRI treatment. Sixteen medication-free OCD patients were randomly assigned to 12 weeks of either CBT or sertraline treatment. Pre-to-post treatment changes in the α-[C]methyl-L-tryptophan brain trapping constant, K* (ml/g/min), were assessed as a function of symptom response, and correlations with symptom improvement were examined. Responders/partial responders to treatment did not show significant changes in relative regional tracer uptake; rather, in responders/partial responders, 12 weeks of treatment led to serotonin synthesis capacity increases that were brain-wide. Irrespective of treatment modality, baseline serotonin synthesis capacity in the raphe nuclei correlated positively with clinical improvement. These observations suggest that, for some patients, successful remediation of OCD symptoms might be associated with greater serotonergic tone.
认知行为疗法（CBT）和选择性 5-羟色胺再摄取抑制剂（SSRIs）都是治疗强迫症（OCD）患者的有效方法，但对于这些治疗方式相关的神经化学变化知之甚少。在这里，我们使用正电子发射断层扫描和α-[C]甲基-L-色氨酸示踪剂来检查强迫症患者在接受 CBT 或 SSRI 治疗后大脑区域 5-羟色胺合成能力的变化。16 名未服用药物的强迫症患者被随机分配接受 12 周的 CBT 或舍曲林治疗。评估了α-[C]甲基-L-色氨酸脑捕获常数 K*（ml/g/min）的治疗前后变化，作为症状反应的函数，并检查了与症状改善的相关性。治疗的应答者/部分应答者的相对区域示踪剂摄取没有明显变化；相反，在应答者/部分应答者中，12 周的治疗导致了广泛的 5-羟色胺合成能力增加。无论治疗方式如何，中缝核的基线 5-羟色胺合成能力与临床改善呈正相关。这些观察结果表明，对于某些患者来说，强迫症症状的成功缓解可能与更高的 5-羟色胺能有关。
