CSF 5-HIAA as a Predictor of Treatment Response in Trichotillomania

In a preliminary study from 1992, researchers investigated the role of cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) as a predictor of treatment response in trichotillomania, a condition characterized by chronic hair-pulling. The study involved 8 medication-free female patients with trichotillomania and matched normal controls. No differences were found between patients and controls in CSF measures of cortisol, 5-HIAA, homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG), nor did these measures correlate with trichotillomania symptomatology. However, the degree of response to serotonin re-uptake inhibitors was significantly correlated with baseline CSF 5-HIAA levels, suggesting that central serotonin turnover was specifically relevant to treatment response in trichotillomania.