Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany.
Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, LMU Munich, Munich, Germany.
Neuropsychopharmacology. 2019 Mar;44(4):660-667. doi: 10.1038/s41386-018-0191-9. Epub 2018 Aug 27.
Use of alcohol, cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs. The exact pathophysiology of abuse or addiction associated with these sedative substances is not completely understood, but previous research implicates the important role of the striatal dopamine system in the addiction process. Multiple studies investigated changes in the striatal dopamine systems of users of sedative substances, but currently these results are very heterogeneous. Therefore, we conducted a meta-analysis of in vivo neuroimaging studies investigating dopaminergic alterations in the striatum of users of alcohol, opioids or cannabis. Analyses for each substance were conducted separately for the availability of D2/D3 dopamine receptors, dopamine transporters and dopamine synthesis capacity. In total, 723 substance users and 752 healthy controls were included. The results indicated a significant lower striatal D2/D3 receptor availability in alcohol users compared to controls (g = 0.46) but no difference in dopamine transporter availability or dopamine synthesis capacity. Our analysis indicated that changes of dopamine receptors and transporters are moderated by the duration of abstinence. Comparing opioid users with controls revealed a significant lower D2/D3 receptor availability (g = 1.17) and a significantly lower transporter availability (g = 1.55) in opioid users. For cannabis users, there was no significant difference in receptor availability compared to controls and too few studies provided information on dopamine transporter availability or synthesis capacity. Our analysis provides strong evidence for a central role of the striatal dopamine system in use of alcohol or opioids. Further studies are needed to clarify the impact of the dopamine system in cannabis users.
使用酒精、大麻和阿片类药物的现象非常普遍，与全球疾病负担和高经济成本有关。滥用或成瘾与这些镇静物质有关的确切病理生理学尚未完全了解，但先前的研究表明纹状体多巴胺系统在成瘾过程中起着重要作用。多项研究调查了镇静物质使用者纹状体多巴胺系统的变化，但目前这些结果非常不一致。因此，我们对研究酒精、阿片类药物或大麻使用者纹状体多巴胺改变的体内神经影像学研究进行了荟萃分析。对于每种物质，分别进行了 D2/D3 多巴胺受体、多巴胺转运体和多巴胺合成能力的可用性分析。总共纳入了 723 名物质使用者和 752 名健康对照者。结果表明，与对照组相比，酒精使用者的纹状体 D2/D3 受体可用性显著降低（g=0.46），但多巴胺转运体可用性或多巴胺合成能力无差异。我们的分析表明，多巴胺受体和转运体的变化受到戒断时间的调节。与对照组相比，阿片类药物使用者的 D2/D3 受体可用性（g=1.17）和转运体可用性（g=1.55）显著降低。与对照组相比，大麻使用者的受体可用性没有显著差异，并且关于多巴胺转运体可用性或合成能力的研究太少。我们的分析为纹状体多巴胺系统在酒精或阿片类药物使用中的核心作用提供了有力证据。需要进一步的研究来阐明多巴胺系统在大麻使用者中的影响。
