The International Journal of Neuropsychopharmacology

Research Article

Comparative efficacy of pregabalin and benzodiazepines in treating the psychic and somatic symptoms of generalized anxiety disorder

R. Bruce Lydiarda1 c1, Karl Rickelsa2, Barry Hermana3 and Douglas E. Feltnera3

a1 Psychiatry/Mental Health Ralph H. Johnson VA Medical Center, Charleston, SC, USA

a2 Department of Psychiatry, University of Pennsylvania Health System, Philadelphia, PA, USA

a3 Pfizer Inc., Groton, CT, USA


Prior research suggests that SSRIs may have greater efficacy for psychic compared to somatic anxiety, while benzodiazepines show greater somatic efficacy. The goal of this analysis was to evaluate the efficacy of pregabalin (PGB) in treating psychic and somatic symptoms of anxiety. Data were combined from six short-term, double-blind, placebo-controlled, fixed-dose trials of PGB in patients with generalized anxiety disorder (GAD). The following PGB daily dose groups were studied: 150 mg (n=210), 300–450 mg (n=455), and 600 mg (n=406), benzodiazepines (6 mg/d lorazepam and 1.5 mg/d alprazolam, n=299), vs. placebo (n=484). Changes in Hamilton Anxiety Rating Scale (HAMA) psychic and somatic anxiety factors and individual items were analysed. Treatment with 300–600 mg PGB significantly improved both the HAMA psychic and somatic anxiety factors. In contrast, treatment with 150 mg PGB appeared to be less effective, achieving significance only on the psychic anxiety factor. PGB (300–450 mg) was associated with significant improvement on 13 out of 14 HAMA items, while treatment with 600 mg PGB was associated with significant improvement in 10 out of 14 HAMA items. Treatment with benzodiazepines was also associated with significant improvement in both psychic and somatic anxiety factors, with significant improvement occurring in 5 out of 14 HAMA items. The results of this pooled analysis indicate that both PGB and benzodiazepines had significant efficacy in treating both HAMA psychic and somatic anxiety. A dose–response effect was evident for PGB that reached a plateau at a dose of 300 mg/d.

(Received March 09 2009)

(Reviewed April 08 2009)

(Revised June 15 2009)

(Accepted July 21 2009)

(Online publication September 09 2009)


c1 Address for correspondence: R. Bruce Lydiard, Ph.D., M.D., Psychiatry/Mental Health Ralph H. Johnson VA Medical Center, 109 Bee St, Charleston, SC 29401-5799, USA. Tel.: 843-789-6744 Fax: 843-789-6290 Email:


Portions of this paper were presented at the Anxiety Disorders Association of America 24th Annual Conference, 11–14 March 2004, Miami, FL; and at the American Psychiatric Association 156th Annual Meeting, 17–22 May 2003, San Francisco, CA.