Quetiapine augmentation of SRIs in treatment refractory obsessive-compulsive disorder: a double-blind, randomised, placebo-controlled study [ISRCTN83050762].
BACKGROUND
Although serotonin reuptake inhibitors are effective in the treatment of OCD, many patients fail to respond to these agents. Growing evidence from open-label and placebo-controlled trials suggests a role for augmentation of SRIs with atypical antipsychotics in OCD. Quetiapine is generally well tolerated and previous open-label data has produced mixed results in OCD and additional controlled data is needed.


METHODS
We undertook a double-blind, randomised, parallel-group, flexible-dose, placebo-controlled study of quetiapine augmentation in subjects who had responded inadequately to open-label treatment with an SRI for 12 weeks. Following informed consent and screening, forty-two subjects were randomised to either placebo or quetiapine for six weeks.


RESULTS
There was significant improvement from baseline to endpoint on the Yale-Brown Obsessive-Compulsive Scale in both the quetiapine and placebo groups (quetiapine, n = 20, p < 0.0001; placebo, n = 21, p = 0.001) with 40% (n = 8) of quetiapine and 47.6% (n = 10) of placebo treated subjects being classified as responders. Quetiapine did not demonstrate a significant benefit over placebo at the end of the six-week treatment period (p = .636). Similarly quetiapine failed to separate from placebo in the subgroup of subjects (n = 10) with co-morbid tics. Quetiapine was generally well tolerated.


CONCLUSIONS
In this study, quetiapine augmentation was no more effective than placebo augmentation of SRIs. A number of limitations in study design make comparisons with previous studies in this area difficult and probably contributed to our negative findings. Future work in this important clinical area should address these limitations.
Carey
Paul D
PD
MRC Research Unit on Anxiety Disorders, University of Stellenbosch, Cape Town, South Africa. pcarey@sun.ac.za
Vythilingum
Bavanisha
B
Seedat
Soraya
S
Muller
Jacqueline E
JE
van Ameringen
Michael
M
Stein
Dan J
DJ
D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D003987:Dibenzothiazepines / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D010919:Placebos; D011569:Psychiatric Status Rating Scales; D000069348:Quetiapine Fumarate; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use*; D017211:Treatment Failure; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D010919:Placebos; D000069348:Quetiapine Fumarate; D017367:Selective Serotonin Reuptake Inhibitors