Lack of seasonal variation in pediatric lumbar cerebrospinal fluid neurotransmitter metabolite concentrations

Seasonal variation of cerebrospinal fluid (CSF) monoamines, particularly 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) has been reported for psychiatrically ill and normal adults. Circannual variability was examined for a group of 72 children (mean age = 159.4 +/- 40.3 (SD), range 77-238 months), with a primary diagnosis of obsessive-compulsive disorder (OCD) or disruptive behavior disorder (DBD) (attention deficit disorder, oppositional disorder and/or conduct disorder), from whom CSF had been obtained systematically. There were no seasonal differences in mean concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG), HVA, or 5-HIAA, either for the group as a whole, for the separate diagnostic (OCD vs DBD) categories or for the pre-pubertal subgroup. Log-corrected HVA concentrations for the Tanner IV and V subgroup differed by season with summer concentrations less than those of fall (P = 0.06) and winter (P = 0.005). The results suggest that pubertal changes may play a role in any expression of circannual variability.