The study includes 2 treatment periods. The open-label run-in period will begin at patient enrolment and continue for 3 weeks, during which all patients will receive once daily treatment with zicronapine. The double-blind period will begin at patient randomization and continue for 5 weeks, during which the patients will be assigned to one group receiving once daily treatment with zicronapine and 3 groups receiving once weekly treatment with zicronapine.
