A significant percentage of violent offenders show evidence of blood-brain barrier dysfunction, according to two studies.
In the most recent of these studies, Henrik Anckarsäter and colleagues evaluated 28 violent and sexual offenders, all but one of them male. All of the subjects were undergoing pretrial psychiatric evaluation at the time, and were later convicted. The researchers measured each subject's cerebrospinal fluid (CSF)/serum albumin ratio, which can be used to assess the integrity of the blood-brain barrier, and compared the measurements to those of non-criminal control subjects. They report that four of the criminals, but none of the controls, had abnormally high CSF/serum albumin ratios, and that as a group the offenders had significantly higher ratios than the controls.
In an earlier study of 19 non-psychotic violent male offenders, the researchers found an even higher percentage of abnormality, with 8 of the subjects having elevated CSF/serum albumin ratios. The researchers say that "current medication or substance abuse did not explain the increase in either study."
Increased CSF/serum albumin ratio has also been reported in suicide attempters, psychotic patients, and people with central nervous system trauma and tumors. The researchers say that "changes in blood brain barrier permeability [are] an unspecific sign that may be explained by various adverse life events and medical conditions. Increased albumin ratios on the group level and clearly pathological states in considerable subgroups (about one in four based on our two study groups) call for attention to the neurological functioning among violent offenders that today receive little medical attention."
"Increased CSF/serum albumin ratio: a recurrent finding in violent offenders," H. Anckarsäter, A. Forsman, and K. Blennow, Acta Neurologica Scandinavica, Vol. 112, No. 1, July 2005, 48-50.
"CSF studies in violent offenders. II. Blood-brain barrier dysfunction without concurrent inflammation or structure degeneration," H. Soderstrom, K. Blennow, A. Manhem, and A. Forsman, Journal of Neural Transmission, Vol. 108, No. 7, 2001, 879-86. Henrik Anckarsäter, the Forensic Psychiatric Clinic, Malmö University Hospital, Sege Park 8A, 205 02 Malmö, Sweden.