Benzodiazepines impair cognitive function, especially in the elderly. The current analysis sought preliminary data on the effect of pregabalin on cognition in elderly patients with GAD.

Patients aged ≥65 years who met DSM-IV criteria for GAD, with HAM-A≥20 and MMSE≥24, were randomized to 8 weeks of treatment with flexible-dosage pregabalin (150-600 mg/d) or placebo. A subgroup (N=89; 81% female; mean age=70.4 years; mean HAM-A=27.3) completed a cognitive battery including the Digit Symbol Substitution Test (DSST) and the Set Test at baseline and endpoint.

At baseline, scores for pregabalin and placebo on the DSST were 13.75±3.51 vs 13.39±3.89 and on the Set Test 37.88±3.25 vs 37.63±3.69. There was significant (P<.05) inverse Pearson correlation between HAM-A item-5 (intellectual) and DSST (-0.32) and Set Test (-0.30) scores. There were also moderate inverse correlations between the DSST and HAM-A total score (-0.35) and age (-0.25). Weaker correlations (with the same directionality) were observed between the Set Test and these variables. At 8-week LOCF-endpoint, scores were comparable on the DSST (13.82 vs 14.54) and the Set Test (38.24 vs 37.95). Endpoint improvement in the HAM-A was moderately correlated with improvement in the Set Test (-0.23, P<.05) but not with DSST. Univariate and multivariate analyses showed treatment with pregabalin had no effect on endpoint cognitive function.

Pregabalin significantly improved the symptoms of GAD in patients aged ≥65 years and caused no impairment of cognitive function. A more extensive cognitive battery is needed to confirm this preliminary finding.