The study is a multicenter, multicountry, randomized, parallel-group, double blind, placebo and paroxetine-controlled study consisting of three segments (A, B, and C). Segment A is a 1-week, placebo, single-blind period and Segment B is an 8-week, double blind period. Patients completing Segment B may be eligible for enrollment into Segment C, a 44-week, double blind extension. All randomized patients must complete a post-study visit 1 week after intake of the last dose of study medication.