A pilot study of the effects of chronic paroxetine administration on hippocampal N-acetylaspartate in generalized anxiety disorder.

The neural basis of generalized anxiety disorder (GAD) is poorly characterized. The effect of chronic administration (12 weeks) of paroxetine, a selective serotonin reuptake inhibitor, on N-acetylaspartate (NAA), a marker of neuronal viability, was evaluated in adults with GAD using proton magnetic resonance spectroscopic imaging ((1)H MRSI) at 1.5 T. We hypothesized that, pretreatment abnormalities in hippocampal NAA/creatine (NAA/Cr) would normalize with symptomatic improvement. Nine GAD patients (mean age = 41.7 year; 4 females) received 12 weeks of open-label paroxetine treatment, flexibly dosed up to 60 mg/day. Clinical outcome was assessed with the Hamilton Anxiety Rating Scale (HAM-A). Multislice ( 1)H MRSI scans were performed at unmedicated baseline and following 6 and 12 weeks of treatment. Ten untreated healthy volunteers (HVs) (mean age = 37.1 year; 4 females) received scans at the same intervals. All patients achieved remission (HAM-A