FIG. 4. Summary of seven studies showing decreased CSF SS in depression. (a) Absolute SS levels in patients and controls. The studies are presented in chronological order. The data in the Sunderland study have been slightly extended in the study by Molchan. The numbers of subjects and controls appear above the standard error bars. (b) The percentage decrease in CSF SS in depression in the same studies. (Adapted from ref. 48)