Non-human primate studies suggest that early environmental influences may have an enduring effect on central serotonin function. Therefore, it was decided to examine in humans whether childhood trauma might be related to cerebrospinal fluid (CSF) concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) as an adult. A total of 29 withdrawn cocaine-dependent patients completed the Childhood Trauma Questionnaire. They also had a lumbar puncture for determination of CSF concentrations of 5-HIAA. CSF concentrations of the dopamine metabolite homovanillic acid (HVA) were also determined. Childhood emotional neglect scores showed significant negative correlations with CSF levels of 5-HIAA and HVA, and patients with emotional neglect scores above the median had significantly lower CSF 5-HIAA and HVA levels than patients with emotional neglect scores at or below the median. These findings suggest the possibility that childhood trauma may have an effect on central monoamine function as an adult.