title: Predictors of placebo response: a retrospective analysis.
abstract: This retrospective evaluation involved 197 patients from independent clinical investigations of four antidepressant medications. Six variables were analyzed for their discriminative utility in predicting placebo response rates: gender; marital status; age; education; duration of illness; and severity of depressive symptomatology, as measured by Hamilton Rating Scale for Depression (HAM-D or HDRS) scores. Men were slightly more responsive to placebo than were women (29.8%, n = 94 vs. 24.3%, n = 103). Married patients demonstrated the highest probability of a positive placebo response (38.15%, n = 76), as compared with widowed/separated/divorced (21.9%, n = 73) or single (16.7%, n = 48) patients. A trend toward an increased probability of placebo response was detected for patients aged 60 and above (35.7%, n = 14). Educational level achieved and duration of illness were not predictive. Severity of illness proved most noteworthy, with the placebo response rate higher in the more mild patients (40.8%, n = 27 vs. 23.4%, n = 77).
authors.affiliation: Pharmacology Research Institute, Long Beach, CA 90807-0289.
authors.forename: C S
authors.initials: CS
authors.lastname: Wilcox
authors.forename: J B
authors.initials: JB
authors.lastname: Cohn
authors.forename: R D
authors.initials: RD
authors.lastname: Linden
authors.forename: J F
authors.initials: JF
authors.lastname: Heiser
authors.forename: P B
authors.initials: PB
authors.lastname: Lucas
authors.forename: D L
authors.initials: DL
authors.lastname: Morgan
authors.forename: D
authors.initials: D
authors.lastname: DeFrancisco
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003866:Depressive Disorder / Q000188:drug therapy* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D012189:Retrospective Studies
chemical_list: D000928:Antidepressive Agents; D010919:Placebos