Multicenter, placebo-controlled, fixed-dose study of citalopram in moderate-to-severe depression

J Clin Psychiatry. 1999 Dec;60(12):824-30. doi: 10.4088/jcp.v60n1204.


Background: Citalopram, the most selective serotonin reuptake inhibitor (SSRI), is a bicyclic phthalane derivative with a chemical structure that is unrelated to that of other SSRIs and available antidepressants. The drug is approved for use in 69 countries. This 6-week, fixed-dose, placebo-controlled, parallel-arm, multicenter trial was performed to confirm its efficacy and safety in treatment of outpatients with major depression in the United States.

Method: Six hundred and fifty adult outpatients with moderate-to-severe major depression (DSM-III-R) were randomly assigned to receive citalopram at doses of 10 mg (N = 131), 20 mg (N = 130), 40 mg (N = 131), or 60 mg (N = 129) or placebo (N = 129) once daily. Outcome assessments were the 21-item Hamilton Rating Scale for Depression (HAM-D), the Montgomery-Asberg Depression Rating Scale (MADRS), and the Clinical Global Impressions scale.

Results: Between-group comparisons of the change from baseline to endpoint revealed significantly greater improvement in the citalopram patients relative to the placebo patients on all 3 efficacy measures. Patients randomly assigned to 40 mg/day and 60 mg/day of citalopram showed significantly greater improvement than placebo on all efficacy measures, as well as on the HAM-D symptom clusters measuring depressed mood, melancholia, cognitive disturbance, and psychomotor retardation. Patients who received 10 mg/day and 20 mg/day of citalopram also showed consistent improvement relative to placebo on all efficacy ratings, with statistical significance demonstrated in the MADRS response rate, the HAM-D depressed mood item, and the HAM-D melancholia subscale. Citalopram was well tolerated, with only 15% of patients discontinuing for adverse events. The side effects most commonly associated with citalopram treatment were nausea, dry mouth, somnolence, insomnia, and increased sweating.

Conclusion: Citalopram was significantly more effective than placebo in the treatment of moderate-to-severe major depression, especially symptoms of depressed mood and melancholia, with particularly robust effects shown at doses of 40 and 60 mg/day. Citalopram was well tolerated in spite of forced upward titration to fixed-dose levels, with a low incidence of anxiety, agitation, and nervousness.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Ambulatory Care
  • Citalopram / administration & dosage*
  • Citalopram / adverse effects
  • Citalopram / therapeutic use
  • Depressive Disorder / drug therapy*
  • Depressive Disorder / psychology
  • Drug Administration Schedule
  • Female
  • Headache / chemically induced
  • Humans
  • Male
  • Nausea / chemically induced
  • Placebos
  • Psychiatric Status Rating Scales
  • Serotonin Uptake Inhibitors / administration & dosage*
  • Serotonin Uptake Inhibitors / adverse effects
  • Serotonin Uptake Inhibitors / therapeutic use
  • Severity of Illness Index
  • Sleep Initiation and Maintenance Disorders / chemically induced
  • Treatment Outcome


  • Placebos
  • Serotonin Uptake Inhibitors
  • Citalopram