The interaction between dopamine transporter function, gender differences, and possible laterality in depression

The Dopamine Transporter (DAT) can reflect the general state of striatal dopamine activity. This current study examined the role of DAT in depressed patients before and after bupropion treatment. Twenty-three patients with major depression were treated with bupropion for 8 weeks. Before and after the treatment, they and 20 normal subjects received the radioligand ^99mTc-TRODAT-1 single photon emission tomography scan (SPECT). Subjects were assessed with the Hamilton Depression Rating Scale. All DAT images were spatially normalized to an averaged brain template, and the specific binding ratios of the striatum, caudate, and putamen were calculated according the formulae of: [region counts] / [occipital counts] - 1. Depressed patients had greater DAT availability on both sides of the striatum. DAT binding was significantly decreased in the striatum after bupropion treatment. Women had higher initial and final DAT binding in the right and left caudate when compared to depressed men. DAT binding decreased in all areas of the brain in women after successful antidepressant treatment, but only in the right caudate of men. Depressed patients had a greater availability of DAT; it was decreased after bupropion treatment.Women seemed to have more DAT availability.