Long-term effects of alprazolam and imipramine on cerebrospinal fluid monoamine metabolites and neuropeptides in panic disorder.

Cerebrospinal fluid (CSF) homovanillic acid, 5-hydroxyindoleacetic acid, 3-methoxy-4-hydroxyphenylglycol, and somatostatin and beta-endorphin levels were measured in 12 patients with panic disorder before and after 7 months of treatment with alprazolam or imipramine. The concentrations of CSF monoamine metabolites and neuropeptides were at baseline of the same order of magnitude in panic patients and controls. Neither alprazolam nor imipramine changed metabolite or neuropeptide levels in CSF despite clinical improvement in both treatment groups. According to present CSF data, the antipanic actions of alprazolam and imipramine do not involve the monoaminergic or peptidergic systems studied.