Do children and adolescents have differential response rates in placebo-controlled trials of fluoxetine?
OBJECTIVE
Recent acute efficacy trials of antidepressants in youth have suggested that high placebo-response rates in children (< 12 years of age) indicate that children may be more responsive to non-specific treatment interventions. Yet, these studies generally have not presented age-specific outcome data. The objective of this study was to compare the efficacy outcomes for children (< 12 years of age) and adolescents (> or = 12 years of age) using the combined data from two previously published double-blind, placebo-controlled trials of fluoxetine.


METHODS
Children (< 12 years of age) and adolescents (> or = 12 years of age) with major depressive disorder were randomized to fluoxetine or placebo for 8-9 weeks of treatment. Outcome was assessed using the Children's Depression Rating Scale-Revised (CDRS-R) and Clinical Global Impressions scale.


RESULTS
Random regression of the CDRS-R showed a treatment group by age group interaction (F(1,338)=4.10, P=.044), indicating that the treatment effect was significantly more pronounced in children than adolescents. Within children, response at exit to fluoxetine was significantly better than placebo (56.9% vs 33.3%; P=.009). Adolescent response rates at exit were not significantly different between the groups (51.1% vs 38.6%; P=.128). Remission rates were low for both groups.


CONCLUSIONS
In the combined fluoxetine trials, drug-placebo difference was greater in children compared with adolescents. Contrary to expectations, the placebo-response rate was lower in the children than the adolescents.
Mayes
Taryn L
TL
Department of Psychiatry, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-8589, USA. taryn.mayes@utsouthwestern.edu
Tao
Rongrong
R
Rintelmann
Jeanne W
JW
Carmody
Thomas
T
Hughes
Carroll W
CW
Kennard
Beth D
BD
Stewart
Sunita M
SM
Emslie
Graham J
GJ
D000293:Adolescent; D000367:Age Factors; D018687:Antidepressive Agents, Second-Generation / Q000627:therapeutic use*; D002648:Child; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D004311:Double-Blind Method; D005260:Female; D005473:Fluoxetine / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015337:Multicenter Studies as Topic; D010552:Personality Assessment; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
D018687:Antidepressive Agents, Second-Generation; D005473:Fluoxetine