The effectiveness of antipsychotic medications in patients who use or avoid illicit substances: Results from the CATIE study
Received 22 October 2007; received in revised form 15 November 2007; accepted 20 November 2007. published online 15 January 2008.
Abstract
Objective
This double-blind study compared a second generation (atypical) antipsychotic drugs compared to a representative older agent for patients with schizophrenia who use or avoid illicit substances.
Methods
Schizophrenic subjects were recruited at 57 U.S. sites and randomly assigned to olanzapine, perphenazine, quetiapine, risperidone or ziprasidone for up to 18 months. The primary aim of this analysis was to delineate differences between the overall effectiveness of these five treatments among patients who used or did not use illicit substances.
Results
There were no significant differences between treatment groups in time to all-cause treatment discontinuation among patients who use illicit drugs (median 3.3 to 6.8 months). Among non-users time to treatment discontinuation was significantly longer for patients treated with olanzapine (median 13.0 months) than perphenazine ( 5.9 months), risperidone (5.6 months), or quetiapine (5.0 months); time to discontinuation for ziprasidone (4.3 months) was even shorter, although the latter difference was not significant. The difference between risperidone and quetiapine, although small, was significant. All remaining differences were non-significant. Similar results were found for discontinuation due to inefficacy. There were no differences between illicit users and non-users in symptom reduction and global improvement, after adjustment for differential duration of treatment. Differences in discontinuation results were attenuated by non-compliance, but the trends persisted after controlling for treatment compliance.
Conclusions
Among patients with chronic schizophrenia who avoid use of illicit drugs, olanzapine was more effective than other antipsychotics as reflected by longer time to all-cause discontinuation, but illicit substance abuse attenuated this advantage, reinforcing the need for concurrent substance abuse treatment.
aDepartment of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham NC, United States
bDepartment of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill, NC, United States
cDepartment of Psychiatry, University of Utah Medical Center, Salt Lake City, UT, United States
dAppalachian Behavioral Healthcare System, Athens OH, United States
eQuintiles Inc., Research Triangle Park, NC, United States
fDepartment of Psychiatry, University of Iowa School of Medicine, Iowa City, IA, United States
gPsychiatric Research Institute, Wichita KS, United States
hDepartment of Psychiatry, Albuquerque Veteran’s Administration Medical Center and the University of New Mexico, Albequerque, NM, United States
iDivision of Services and Intervention Research, National Institute of Mental Health, National Institutes of Health, Bethesda, United States
jDepartment of Psychiatry, College of Physicians and Surgeons, Columbia University, New York State Psychiatric Institute, New York, United States
Corresponding author. Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, DUMC Box 3173, Durham, NC 27710, United States. Tel.: +1 919 684 8676; fax: +1 919 681 7504.
1 The CATIE Investigators are listed in the Acknowledgements.
ABSTRACT