BUPROPION SLOW-RELEASE RESPONSE IN DEPRESSION - DIAGNOSIS AND BIOCHEMISTRY

Background: Bupropion has been previously shown to be particularly ben eficial in bipolar and atypical depression. Previous research has supp orted a possible association of response to plasma levels and to chang es in plasma homovanillic acid (HVA). These findings were here extende d to bupropion slow-release (SR), a formulation with slower release ki netics. Methods: Forty-one patients with major depressive disorder (DS M-III-R) completed 8 weeks of a fired dose of 300 mg/day in two doses/ day. Clinical outcome measures were the Hamilton Depression Rating Sca le (HDRS) and Beck Depression Inventory (BDI). Biological parameters i ncluded plasma HVA and 3-methoxy-4-hydroxyphenylglycol (MHPG), as well as a final measurement of plasma bupropion and its metabolites. Resul ts: Response to bupropion SR differed among the three groups: results for change in HDRS and in BDI were greater in the bipolar and atypical than in the ''typical'' depressed patients. Mean change in HDRS was, respectively, of 15.6, 17.1, and 7.6 (F = 5.57, p < .01); mean change in the BDI, 21.1, 16.9, and 7.3 (F = 3.32, p < .05). Threobupropion le vels correlated with HDRS scores (r = .47, p = .02, n = 23); plasma HV A and MHPG increased significantly (t = 2.31, p = .03; t = 2.15 p = .0 4, n = 17). Bipolar depressed patients' improvement in HDRS was relate d to increases in MHPG (r = .87, p = .01) and in HVA (r = .70, p = .08 ). Conclusions: This fixed-dose study indicates that there may be spec ific benefits for bupropion SR in atypical and bipolar depression, and that these benefits may be related also to plasma levels and biochemi cal changes in catecholamines. Due to the small sample size, replicati on is of key importance. (C) 1998 Society of Biological Psychiatry.