Antipsychotic effects of quetiapine in naturalistic long term follow up study.
OBJECTIVE
This study aimed to examine the effectiveness of quetiapine and the effects of dosage relates to its effectiveness on schizophrenia and schizoaffective disorder in a naturalistic setting in Korean people.


METHODS
This study was a 24-week, open-label, non-comparative, naturalistic study of quetiapine in patients diagnosed with schizophrenia and schizoaffective disorder according to DSM-IV. We stratified the patients into mild [(clinical global impression severity (CGI-S) <4 at baseline)] and severe groups (CGI-S >/=4 at baseline). We investigated the response rate, defined as clinical global impression improvement (CGI-I) </=2, in the severe group and the aggravation rate in the mild group using the last-observation-carried-forward (LOCF) and the Kaplan-Meier method (K-M).


RESULTS
During the 24 weeks, 151 (18.4%) of the participants dropped out of the study. There was a significant decrease in the mean CGI-S score, from 4.5+/-1.1 at baseline to 2.8+/-1.1 at 24 weeks. The response rate of severe group was 54.5% (estimated by LOCF) and 73.3% (K-M estimated) at 24 weeks. All patients who completed the study had taken a mean quetiapine dosage of 507.9+/-245.9 mg daily. The decrease of CGI-S score in high-dose group (the maximum dose was 750 mg/d or above) was statistically significant than that in recommended-dose group (the maximum dose was less than 750 mg/d).


CONCLUSIONS
This study demonstrated the long-term effectiveness of quetiapine in the treatment of schizophrenia and schizoaffective disorder in a naturalistic setting in Korean people. This study suggests that higher than recommended quetiapine dosages could be more effective in some patients.
Lee
Jung-Sun
JS
Department of Psychiatry, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
Ahn
Joon Ho
JH
Kim
Do-Hoon
DH
Kim
Jong-Jin
JJ
Kim
Tae-Young
TY
Yoo
So-Young
SY
Lee
Dong-Geun
DG
Lee
Sang-Hyuk
SH
Lim
Se-Won
SW
Lim
Weon-Jeong
WJ
Jung
Il-Kyung
IK
Jung
Hae-Kyung
HK
Cho
Dong-Hwan
DH
Cho
In-Hee
IH
Kim
Chang-Yoon
CY