Placebo response in panic disorder. A review

Abstract

SummaryA short review of placebo response in double-blind placebo-controlled therapeutic panic disorder studies published since 1985 is given. The main result is that the inefficacy-related drop-out rate of the placebo group of almost all clinical studies grows to more than 30% after 4-5 weeks of treatment and that often the results of placebo responders do not widely differ from that of the treatment groups. Except in some studies with very large sample sizes, the described response of the placebo group will not lead to significant differences between placebo and drug in completer analysis, making last observation carried forward (LOCF) analysis necessary. However, the large drop-out rates may lead to invalid efficacy results in later stages of the studies. As it can be shown that the inefficacy-related drop-out rates between placebo and target drug groups are as good an efficacy characteristic as any other, more conventional efficacy parameters, it is proposed to use the inefficacy related drop-out rate as the main efficacy parameter in placebo-controlled panic disorder studies of more than 4-5 weeks.

Anger Treatment in Chemically-Dependent Inpatients: Evaluation of Phase Effects and Gender

“…Dropout rates in substance abuse programs can be even higher (Craig, 1985). No-treatment and placebo controls are especially vulnerable to such attrition (Loo, Poirier-Littre, Theron, Rein and Fleurot, 1997; Mason, 1999; Merz, 1994).…”

Cardio‐respiratory and other symptom clusters in panic disorder

“…(300.21, 300.01 and 300.2; Merz et al, 1993Merz et al, , 1994. The sample characteristics are given in Table I. Due to missing data, only 330 of 332 patients could be evaluated.…”