CSF 5-HIAA as a predictor of treatment response in trichotillomania.

Trichotillomania is characterized by chronic hair-pulling resulting in noticeable hair loss. In a preliminary study, cerebrospinal fluid (CSF) measures in 8 medication-free, female, trichotillomania patients were compared to those of matched, normal controls. There was no difference between patients and controls in measures of CSF cortisol, 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG). CSF measures did not correlate with measures of trichotillomania symptomatology. However, degree of response to treatment with serotonin re-uptake inhibitors significantly correlated with baseline CSF 5-HIAA. This suggests that central serotonin turnover is specifically relevant to treatment response to serotonin re-uptake inhibitors in trichotillomania.