title: N-acetyl-aspartate levels in the dorsolateral prefrontal cortex in the early years of schizophrenia are inversely related to disease duration.
abstract: Magnetic resonance spectroscopy studies in schizophrenia have revealed consistently reduced N-acetyl aspartate (NAA) levels in chronic patients, but not in recent-onset patients. Studies on the relationship between this marker and disease duration have commonly been negative, although it is also true that they have been conducted in patients with long-standing disease. We compared NAA levels in the dorsolateral prefrontal cortex in 16 recent-onset patients (duration: 1.8+/-0.6 years), 19 chronic patients (duration: 9.7+/-6.1 years), and 20 healthy controls. We studied the NAA/creatine and choline/creatine ratios in the dorsolateral prefrontal cortex in both hemispheres, controlling for the effect of age. Chronic patients had significantly lower NAA/Cr ratios in the left hemisphere compared to recent-onset patients and healthy controls, with no difference in Cho/Cr ratio. There were no differences between controls and recent-onset patients. There was a significant inverse relationship between left-side NAA/Cr and disease duration, suggesting that prefrontal NAA levels may progressively decrease in schizophrenia. Taken within the context of the existing literature, these results indicate that this process may be limited to the early years following the onset of the disease. Therefore, reduced prefrontal levels of NAA may be limited to chronic schizophrenia patients.
authors.affiliation: Department of Psychiatry, Hospital Clínico, Paseo de S. Vicente 58-182, Salamanca 37007, Spain. vmolinarod@wanadoo.es
authors.forename: Vicente
authors.initials: V
authors.lastname: Molina
authors.forename: Javier
authors.initials: J
authors.lastname: Sánchez
authors.forename: Santiago
authors.initials: S
authors.lastname: Reig
authors.forename: Javier
authors.initials: J
authors.lastname: Sanz
authors.forename: Carlos
authors.initials: C
authors.lastname: Benito
authors.forename: Cristina
authors.initials: C
authors.lastname: Santamarta
authors.forename: Javier
authors.initials: J
authors.lastname: Pascau
authors.forename: Fernando
authors.initials: F
authors.lastname: Sarramea
authors.forename: Juan D
authors.initials: JD
authors.lastname: Gispert
authors.forename: José M
authors.initials: JM
authors.lastname: Misiego
authors.forename: Tomás
authors.initials: T
authors.lastname: Palomo
authors.forename: Manuel
authors.initials: M
authors.lastname: Desco
mesh_terms: D000328:Adult; D000367:Age Factors; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D002908:Chronic Disease; D003401:Creatine / Q000378:metabolism; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000378:metabolism / Q000503:physiopathology; D018967:Risperidone / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology*; D013997:Time Factors
chemical_list: D014150:Antipsychotic Agents; D001224:Aspartic Acid; C000179:N-acetylaspartate; D018967:Risperidone; D003401:Creatine; D002794:Choline