Plasma norepinephrine in chronic schizophrenia. Several lines of evidence indicate altered noradrenergic function in schizophrenia. The authors examined resting, standing, and change (standing minus resting) in plasma norepinephrine levels in 14 drug-free patients with chronic schizophrenia or schizoaffective disorder and in 33 age- and sex-matched healthy volunteers. Schizophrenic patients had significantly higher resting and standing plasma norepinephrine levels and significantly greater change. Resting and standing levels were significantly related to positive and negative symptoms. There was a significant positive correlation between resting plasma and CSF norepinephrine levels and a significant negative correlation between CSF homovanillic acid and resting, standing, and change in plasma norepinephrine levels. 