精神分裂症的認知衰退

Cognitive Decline in Schizophrenia

目的：由於精神分裂症患者預後與其認知缺損有高度相關，有越來越多的研究關注於此。本篇回顧精神分裂症的認知缺損變化，認知缺損老年患者跟典型失智症－－阿茲海默氏病－－的不同，及發生認知衰退的用藥。方法：使用與目的相關的關鍵字在PubMed醫學文獻檢索系統搜尋。結果：精神分裂症患者首次發病時已有認知缺損，之後能維持穩定，甚至在治療後有進步，在大於等於50歲所謂晚期生活精神分裂症的報告較為歧異，衰退多在65歲附近開始，長期機構化及晚發型的患者有較早較高發生認知衰退的機會。精神分裂症老人以神經病理學診斷為阿茲海默氏病的發生率跟沒有精神疾病的老人相仿；而有明顯認知缺損的精神分裂症老人在腦部神經病理學上的表現跟阿茲海默氏病不同，兩者為不同的疾病。目前無標準治療，同一般對老年精神分裂症的原則，建議可降低抗精神藥劑量，減少使用抗膽鹼藥物。結論：使用適合精神分裂症的認知評估工具做全面性研究將有助於確切診斷和發展治療。

Purposes: An increasing amount of research has been conducted on schizophrenia and associated cognitive functions since the high correlation between cognitive impairment and functional outcome in schizophrenia patients has been confirmed. This article reviews the cognitive change in the schizophrenia, the difference between schizophrenia with cognitive impairment and a typical dementia--Alzheimer’s disease (AD)--in the elderly, and suggestions for drug treatment for elderly schizophrenic patient with cognitive decline. Methods: A search of PubMed databases using relevant keywords was conducted. Results: Individuals with first-episode schizophrenia show cognitive impairment. Cognitive function is not progressive in the initial course and even improves after treatment in some patients. Reports of late-life schizophrenia, that is, in patients aged 50 years and above, showed varied results. Most of these patients with cognition decline began at approximately 65 years of age. Long-term institutionalized and late-onset schizophrenic patients have early onset and higher rate of cognitive decline. The neuropathologic diagnosis of AD was similar in elderly schizophrenic patients and in the elderly without psychiatric disorders. Postmortem neuropathologic studies have revealed different findings regarding elderly schizophrenic patients with cognitive impairment and AD patients. Elderly schizophrenia with cognitive impairment and AD are different diseases. There has been no standard treatment for cognitive decline in schizophrenia patients until now. Typically, decreased dosage of anti-psychosis drugs and the use of less anti-cholinergic drugs are recommended as treatment options for elderly schizophrenic patients. Conclusions: Comprehensive studies using cognitive assessment tools specific to schizophrenia should be useful to precise diagnosis and treatment development.