Cerebrospinal fluid somatostatin, mood, and cognition in multiple sclerosis

Background: Cerebrospinal fluid (CSF) somatostatin (SS) levels have been sh own to be decreased in multiple sclerosis (MS) during relapse as well as in disorders characterized by depression or cognitive impairment. Since MS is often associated with depression and cognitive impairment, we examined bot h the effect of course of illness on CSF SS as well as the variance in SS a ttributable to associated features (e.g., depression or cognitive impairmen t). Methods: Fifteen patients with chronic progressive MS participating in a 2- year cyclosporine trial underwent lumbar punctures for CSF SS at baseline a nd at 12 and 24 months. Additionally, patients were evaluated by neuropsych ological testing, and physical disability and mood ratings. Baseline CSF SS levels were also obtained in a group of control subjects (n = 10). Results: At baseline, CSF SS levels were lower in MS patients than control subjects (p <.001). Decreaed CSF SS at 24 months was correlated with decrea sed cognitive performance on several measures and was best and significantl y predicted by cognitive deterioration at 24 months. Conclusions: Our data support those from previous studies that found lower levels of CSF SS in MS during relapse and suggest that changes in CSF SS ar e related to the process responsible for diminished cognitive function in M S. Biol Psychiatry 1999;46:551-556 (C) 1999 Society of Biological Psychiatr y.