Postmortem serotonin (5-HT) concentrations in the cerebrospinal fluid of medicolegal cases

In a medicolegal study the postmortem serotonin (5-HT) cerebrospinal fluid (CSF) concentrations were determined in routine autopsies using a high performance liquid chromatographic procedure with electrochemical detection. There was no correlation between 5-HT concentrations and age, sex or blood alcohol concentration using a postmortem delay < or = 3 days. In suicides the suboccipital CSF concentrations were significantly decreased compared to the levels measured in the control group (8.55+/-5.99 ng/ml versus 20.15+/-13.56 ng/ml). Additionally, a decrease of 5-HT was found in the suboccipital CSF of opiate fatalities (15.56+/-13.52 ng/ml). The results support the hypothesis that decreased 5-HT concentrations in the CSF are characteristic in suicides. However, due to a rather broad overlapping of values between suicides and controls the results failed to define a possible cut-off level in the 5-HT CSF concentration to distinguish between a suicidal and a non-suicidal incident.