Department of Psychiatry,Office Médico-Pédagogique Research Unit, School of Medicine, University of Geneva,Geneva,Switzerland.
Psychol Med. 2017 Jun;47(8):1442-1453. doi: 10.1017/S0033291716003482. Epub 2017 Jan 23.
Alterations of the reward system have been proposed as one of the core mechanisms underlying the expression of negative symptoms in schizophrenia. Specifically, deficits in specific reward components and white matter (WM) integrity of the reward system have been highlighted. The putative link between negative symptoms and the hedonic experience, or structural connectivity of the reward system has never been examined in the 22q11.2 deletion syndrome (22q11DS), a condition with increased risk for psychosis.
Anticipatory and consummatory dimensions of pleasure were assessed in participants with 22q11DS (N = 54) and healthy controls (N = 55). In patients with 22q11DS, the association between pleasure scores and positive or negative symptoms was investigated. Furthermore, WM integrity of the accumbofrontal tract was quantified using diffusion tensor imaging (DTI). Associations between DTI measures, pleasure dimensions and negative symptoms were examined.
Patients with 22q11DS showed reduced anticipatory and consummatory pleasure compared to controls. Furthermore, anticipatory pleasure scores were negatively correlated to negative and positive symptoms in 22q11DS. WM microstructural changes of the accumbofrontal tract in terms of increased fractional anisotropy and reduced radial anisotropy were also identified in patients. However, no significant correlation between the DTI measures and pleasure dimensions or psychotic symptoms was observed.
This study revealed that participants with 22q11DS differed in their experience of pleasure compared to controls. The anticipatory pleasure component appears to be related to negative and positive symptom severity in patients. Alterations of WM integrity of the accumbofrontal tract seem to be related to myelination abnormalities in 22q11DS patients.
奖赏系统的改变被认为是精神分裂症阴性症状表现的核心机制之一。具体而言，已经强调了奖赏系统特定奖赏成分和白质（WM）完整性的缺陷。在 22q11.2 缺失综合征（22q11DS）中，尚未研究阴性症状与享乐体验或奖赏系统的结构连接之间的潜在联系，22q11DS 是一种精神病风险增加的病症。
在 22q11DS 患者（N=54）和健康对照组（N=55）中评估了预期和满足维度的愉悦感。在 22q11DS 患者中，研究了愉悦感评分与阳性或阴性症状之间的关联。此外，还使用弥散张量成像（DTI）量化了伏隔核额皮质束的 WM 完整性。检查了 DTI 测量值、愉悦维度和阴性症状之间的关联。
与对照组相比，22q11DS 患者表现出预期和满足愉悦感降低。此外，22q11DS 患者的预期愉悦感评分与阴性和阳性症状呈负相关。还在患者中确定了伏隔核额皮质束的 WM 微观结构变化，表现为各向异性分数增加和各向异性分数减少。然而，没有观察到 DTI 测量值与愉悦维度或精神病症状之间的显著相关性。
本研究表明，与对照组相比，22q11DS 患者在愉悦感体验上存在差异。预期愉悦感成分似乎与患者的阴性和阳性症状严重程度有关。伏隔核额皮质束 WM 完整性的改变似乎与 22q11DS 患者的髓鞘异常有关。
