Dementia-related psychosis (DRP) is prevalent across dementias and typically manifests as delusions and/or hallucinations. The mechanisms underlying psychosis in dementia are unknown; however, neurobiological and pharmacological evidence has implicated multiple signaling pathways and brain regions. Despite differences in dementia pathology, the neurobiology underlying psychosis appears to involve dysregulation of a cortical and limbic pathway involving serotonergic, gamma-aminobutyric acid ergic, glutamatergic, and dopaminergic signaling. Thus, an imbalance in cortical and mesolimbic excitatory tone may drive symptoms of psychosis. Delusions and hallucinations may result from (1) hyperactivation of pyramidal neurons within the visual cortex, causing visual hallucinations and (2) hyperactivation of the mesolimbic pathway, causing both delusions and hallucinations. Modulation of the 5-HT2A receptor may mitigate hyperactivity at both psychosis-associated pathways. Pimavanserin, an atypical antipsychotic, is a selective serotonin inverse agonist/antagonist at 5-HT2A receptors. Pimavanserin may prove beneficial in treating the hallucinations and delusions of DRP without worsening cognitive or motor function.

中文翻译：

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痴呆相关精神病和匹马万色林的潜在作用

痴呆症相关精神病 (DRP) 在痴呆症中普遍存在，通常表现为妄想和/或幻觉。痴呆症的潜在机制尚不清楚；然而，神经生物学和药理学证据涉及多个信号通路和大脑区域。尽管痴呆症的病理学存在差异，但精神病的神经生物学似乎涉及涉及 5-羟色胺能、γ-氨基丁酸能、谷氨酸能和多巴胺能信号传导的皮质和边缘通路的失调。因此，皮质和中脑边缘兴奋性张力的不平衡可能会导致精神病症状。妄想和幻觉可能是由于（1）视觉皮层内锥体神经元的过度激活，导致视觉幻觉和（2）中脑边缘通路的过度激活，造成妄想和幻觉。5-HT 的调制2A受体可以减轻两种精神病相关途径的过度活跃。Pimavanserin 是一种非典型抗精神病药，是 5-HT 的选择性 5-羟色胺反向激动剂/拮抗剂2A受体。Pimavanserin 可能对治疗 DRP 的幻觉和妄想有益，而不会恶化认知或运动功能。