Clinical efficacy of paroxetine in resistant depression.

The antidepressant effects of a specific reuptake inhibitor of 5-hydroxytryptamine (5-HT), paroxetine, were tested in 24 patients with resistant depression who had failed to respond to conventional antidepressants after at least 4 weeks of treatment. A novel exper imental design was chosen in which all patients had 12 weeks of treatment beginning and ending with placebo therapy with 6 weeks of active drug treatment at some point in between. Ratings of depressive symptoms were made using the Hamilton rating scale (HRS) for depression, and the checklist for unwanted effects and their severity was also recorded before and during treatment at 2 week intervals. The change from placebo to active paroxetine therapy was made using a double-blind procedure. Patients who made a significant placebo response in the first 2 weeks of treatment were excluded from further analysis; 20 patients completed the study and satisfied all criteria for inclusion. Both groups of showed a significant improvement in symptoms after 4 weeks of paroxetine therapy. There were no significant treatment differences between the groups, but improvement in symptoms occurred sig nificantly later in the patients who had a longer period of initial placebo therapy. The experimental design also allowed study of withdrawal effects after stopping active treatment. There was no increase in adverse effects, including a subgroup associated with withdrawal problems, either during treatment with paroxetine or after the drug was stopped. The results suggest that paroxetine is probably an effective antidepressant, is well tolerated and has few adverse effects.