• forensic psychiatry;
  • blood–brain barrier;
  • cerebrospinal fluid;
  • brain;
  • central nervous system;
  • aggression

Objective –  To test the hypothesis that cerebrospinal fluid (CSF)/ serum albumin ratios are increased in violent offenders.

Subjects and methods –  In a previous study of violent offenders, we found significantly higher CSF/serum album ratios (as a sign of increased blood–brain barrier permeability) in violent offenders than in healthy controls. For the present replication study, we recruited a new group of 28 violent offenders, aged 45 years or younger, and 20 new control subjects.

Results –  The albumin ratio was again significantly higher in the offender group (mean 6.2) than in the control group (mean 4.6) (P = 0.012). Substance abuse or current medication did not appear to explain this finding.

Conclusion –  Increased CSF/serum albumin ratios are an unspecific sign of neurological dysfunction in subgroups of violent offenders.