Objective: Mirtazapine is a newly introduced antidepressant in Korea. The purpose of
this study is to evaluate effectiveness and safety of mirtazpine as an antidepressant for
the first time in Korean patients with major depression. Methods: This study is an
open, non-comparative, multicenter study treated with mirtazapine for 6 weeks in
patients with DSM-Ⅳ diagnosis of major depression who have 17 item-HAMD score
18 and who are between 18 and 65 years of age. Mirtazapine was administered 30㎎
orally as an initial dose and could be increased to 45 ㎎ form the 14th day of treatment,
depending on the therapeutic responses of subjects. The clinical efficacy of mirtazapine
was assessed at the baseline and at the 1st, 2nd, 4th, and 6th week of treatment. To
assess the clinical efficacy of the drug, well-trained psychiatrists have evaluated
subjects using 17 item-HAMD and CGI on each evaluation periods. Also, for the
evaluation of subjective symptoms of patients, BDI was used. Adverse experiences
associated with mirtazapine were evaluated on each visit, with recordings of blood
pressure, heart rate and weight. The responders were defined as patients with 50%
decrease form baseline in total 17 item-HAMD scores and remitted patients with a total
17 item-HAMD score of 7. Results: Out of 79 subjects enrolled, 45 were completed
this study. After 6 weeks, the score of 17 item-HAMD, CGI, and BDI demonstrated
statistically significant decrease compared with at the baseline. This decrease was
observed as early as the 1st week of mirtazapine treatment. Moreover, the meaningful
reduction in each total scores of these different parameters on each evaluation period
could be detected, except in case of 2-4 week and 4-6 week of BDI. The responder rate
was 15.6% at the first week of mirtazapine treatment , 88.9% at the 6th week. The rate
of remission was 2.2% at the first week and 60.0% at the 6th week. The most frequent
adverse events during 6 weeks were somnolence (31.6%), drowsiness (19%) and weight
gain (17.7%). Aside from sedation and weight gain, anticholinergic, cardiovascular and
stimulating side effects are less than 10%, and no one complained about sexual
dysfunction. The dropouts (34 subjects, 43%) were caused by adverse events (38.2%),
insufficient compliance(35.3%) and uncooperation with the study (20.6%). Conclusion:
Mirtazapine has shown to have superior antidepressant effect in this study. Especially,
this effect appeared form the early treatment phase, the 1st seek of treatment. The most
frequent adverse events reported were somnolence, drowsiness and weight gain.
Anticholinergic, cardiovascular, stimulating adverse events as well as sexual dysfunction
were rarely reported, and there was no clinical significant change on physical
examinations. Therefore this study showed that mirtazapine is a superior and safe
antidepressant in patients with major depression.