For subjects who were classed as non-responders at Week 8, paroxetine at 30 to 40mg/day (once daily) or placebo (once daily) was orally administered with flexible titration regimen for 4 weeks (fixed dose was adopted in the Treatment phase). The subjects underwent a taper phase in case they received Paroxetine 40mg/day, paroxetine 30mg/day or placebo at treatment completion or study withdrawal. A follow-up examination was conducted after 1 to 5 weeks from the last dose of the investigational product.