CRP and depressive symptom measurement: In patients with depression, meta-analyses found statistically significant elevations of Il - 6 in cerebrospinal fluid (CSF) particularly in suicide attempters - in the control group, Il - 6 levels were around 11 pg/mg protein, and in adolescent suicide victims about 25 pg/mg protein, while a study of CRP levels in CSF from a total of 13 541 patients found that 58% had elevated CRP >1 mg/l and 27% had CRP > 3 mg/l (64, 65).