To participate in the study the subjects must be at least 18 years old and give a written informed consent after an oral and written explanation of the study aims and methods. The study sample will include the female and male patients with panic disorder or major depression diagnosis according to DSM-IV criteria. Patients will be recruited from the out- and inpatients services of the Psychiatric Clinic of the Tartu University Hospital. For the detailed assessment of clinical severity of specific disorder and treatment effects the disorder-specific rating scales: Montgomery-Asberg's Depression Rating Scale (MADRS), Clinical Global Impression scale (CGI) will be used. The adverse effects will be evaluated by letting the patients to fill the checklist of side-symptoms. In both patient groups (with panic disorder and major depression) an SSRI escitalopram (Cipralex) will be administrated for 12 weeks in flexible dose ranging between 10 - 20 mg/per day. At the end of week 12 the patients will defined as responders if the decrease in MADRS scores is at least 50% and score on the CGI improvement scale is 2 or less. The remitters will defined if the scores are less than 12 on the MADRS. Patients who do not meet these criteria will defined as non-responders and non-remitters respectively. Depressive patients, showing non-response to escitalopram monotherapy will given the combination of 20 mg of escitalopram and 150-300 mg of bupropion (Wellbutrin SR) for 6 weeks.
