Background

Dopamine activity has been associated with the response to antipsychotic treatment. Our study used a four-parameter model to test the association between the striatal decarboxylation rate of ¹⁸F-DOPA to ¹⁸F-dopamine (k₃) and the effect of treatment on psychotic symptoms in antipsychotic-naïve patients with first-episode psychosis. We further explored the effect of treatment with a partial dopamine D₂ receptor agonist (aripiprazole) on k₃ and dopamine synthesis capacity (DSC) determined by the four-parameter model and by the conventional tissue reference method.

Methods

Sixty-two individuals (31 patients and 31 control subjects) underwent ¹⁸F-DOPA positron emission tomography at baseline, and 15 patients were re-examined after 6 weeks. Clinical re-examinations were completed after 6 weeks (n = 28) and 6 months (n = 15). Symptoms were evaluated with the Positive and Negative Syndrome Scale.

Results

High baseline decarboxylation rates (k₃) were associated with more positive symptoms at baseline (p < .001) and with symptom improvement after 6 weeks (p = .006). Subregion analyses showed that baseline k₃ for the putamen (p = .003) and nucleus accumbens (p = .013) and DSC values for the nucleus accumbens (p = .003) were associated with psychotic symptoms. The tissue reference method yielded no associations between DSC and symptoms or symptom improvement. Neither method revealed any effects of group or treatment on average magnitudes of k₃ or DSC, whereas changes in dopamine synthesis were correlated with higher baseline values, implying a potential effect of treatment.

Conclusions

Striatal decarboxylation rate at baseline was associated with psychotic symptoms and treatment response. The strong association between k₃ and treatment effect potentially implicate on new treatment strategies.

中文翻译：

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在部分多巴胺 D2 受体激动剂治疗前后用正电子发射断层扫描评估未使用抗精神病药物的患者的多巴胺能活性：与精神病症状和治疗反应的关联

背景

多巴胺活性与对抗精神病药物治疗的反应有关。我们的研究使用四参数模型来测试¹⁸ F-DOPA 与¹⁸ F-多巴胺 (k ₃ ) 的纹状体脱羧率与治疗对首发精神病患者的精神病症状的影响之间的关联。我们进一步探讨了用部分多巴胺D ₂受体激动剂（阿立哌唑）治疗对由四参数模型和常规组织参考方法确定的k _{3和多巴胺合成能力（DSC）的影响。}

方法

62 名患者（31 名患者和 31 名对照受试者）在基线时接受了¹⁸次 F-DOPA 正电子发射断层扫描，15 名患者在 6 周后重新检查。6周（ n  = 28）和6个月（n  = 15）后完成临床复查。用阳性和阴性症状量表评估症状。

结果

高基线脱羧率 (k ₃ ) 与基线时更多的阳性症状 ( p < .001) 和 6 周后症状改善 ( p  = .006) 相关。亚区域分析显示，壳核 ( p  = .003) 和伏隔核 ( p = .013) 的基线 k _{3和伏隔核 (} p = .003) 的 DSC 值 与精神病症状相关。组织参考方法没有得出 DSC 与症状或症状改善之间的关联。_{两种方法均未显示组或治疗对 k 3}平均量值的任何影响或 DSC，而多巴胺合成的变化与较高的基线值相关，这意味着治疗的潜在效果。

结论

基线纹状体脱羧率与精神病症状和治疗反应相关。k ₃与治疗效果之间的强关联可能暗示新的治疗策略。