The association of urinary 5-hydroxyindoleacetic acid and vanillylmandelic acid in patients with generalized anxiety.

There is evidence that serotonin and norepinephrine are in some way involved in the pathophysiology of anxiety disorders. Urinary levels of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and the norepinephrine metabolite vanillylmandelic acid (VMA) were measured in 46 patients with generalized anxiety disorder. There was a significant association between urinary levels of 5-HIAA and VMA: r = 0.79; p = 0.0001. Possible implications of this finding are discussed.